By JEFF MAY

Pet rocks. Cabbage
Patch Kids. The Rubik’s Cube. The marketplace, like the Billboard
charts, is full of one-hit wonders—products that come out of nowhere,
capture the national imagination, then just as quickly turn into punch
lines and trivia answers.

But what about the entrepreneurs behind these creations? What do they do after the novelty of their novelty products wears off?

We decided to find out. We tracked
down four people who introduced some of the most popular fad items of
the past few decades to find out how they handled their sudden
prosperity—and rapid exit from the limelight. Some were relaxing and
enjoying their spoils. Others were trying to capture lightning in a
bottle one more time.

Here are their stories.

Stuck on Poetry

A sneeze helped make Dave Kapell the spiritual bard of the refrigerator door.

Back in 1993, the Minneapolis native
was an aspiring musician who liked to cut up his diaries and rearrange
the words to create song lyrics. But he was prone to allergies and, with
the pollen count soaring one day, he sneezed and scattered an
almost-finished song. An idea was born: Why not stick magnets on the
bits of paper and affix them to a cookie sheet to keep them in place?

The contraption stayed in Mr. Kapell’s room for a few months until he
threw a house party and needed the cookie sheet for baking. The word
magnets went up on the refrigerator—and throughout the night, Mr.
Kapell’s friends kept stealing back to the kitchen to scramble the
lyrics. The next day, he got a half-dozen orders for the magnet kits.

“Within a month of the party, it was like I was selling drugs out of
my house,” says Mr. Kapell, who is 48. “It went viral before viral was a
term.”

Soon he was making more from his Magnetic Poetry kits than from his $8-an-hour job in data entry, which he promptly quit.

Friends in retail said he might not have a lot of time to exploit his
big opportunity. So, he pored over books on start-ups and worked
90-hour weeks to build the brand. By 1995, Mr. Kapell and a partner had
set up a company, U.S. Magnetix, to produce custom magnets in China. To
get prime placement for his kits, he prowled gift-shop conferences and
craft fairs, where he found himself treated like the rock god he once
dreamed of becoming.

“I knew that I had hit an atypical home run,” he says. “At trade shows, everyone would say, ‘Everyone wants to be you.’ “

Mr.
Kapell wooed big chain bookstores to get prime locations in their
checkout aisles but didn’t ignore mom-and-pop stores. He says his close
relationship with that close-knit segment has kept copycat products off
the shelves.

To encourage repeat customers, Mr. Kapell started brainstorming new
ideas, such as packs with oversize words for kids, foreign-language
versions and ones with themes such as geeks, Christmas and bike lovers.
“I don’t necessarily like the business side of this,” he says. “Dotting
the i’s and crossing the t’s is not what I’m best at. But I like coming
up with new products.”

That urge, however, led to some missteps. In the late 1990s, Mr.
Kapell tried to develop a software version of the poetry kits, as well
as a game. Both led to steep losses. Another venture, Poetry Stones—a
kit that let crafters frame their messages in quick-set cement—was
initially successful but tailed off quickly.

These days, the recession has hurt sales, as
have the tenuous fortunes of his two biggest customers, Borders and
Barnes & Noble. Mr. Kapell says he is looking to broaden
distribution and is considering a Magnetic Poetry app for the iPhone and
iPad. He’s also making changes in his company’s online store to make
direct sales easier.

In general, though, he says he’s content to issue a half-dozen or
more variations on the original kit each year. A zombie-themed kit is
popular, he says, and erotic-word versions are perennial favorites. A
recent golf-lovers’ kit, on the other hand, was a dud.

Mr. Kapell wouldn’t respond to questions about exactly how much he’s
made from the kits. But, he says, even with the current slowdown,
profits from Magnetic Poetry have allowed him to play gigs more than he
ever could as a struggling musician. He frequently plays ukulele with a
local burlesque troupe and drags along a vintage stand-up bass on
camping trips with friends. His house is decked out with a grand piano
and a 70-piece ukulele collection.

And he thinks the business has staying power. “It’s not a pet rock,”
Mr. Kapell says. “It actually has utility. We get letters from people
every day who are fans.”

It’s All In the Wrist

Robert Croak had built a nice business marketing novelty
products, but he wanted something that could lift his company into the
big leagues.

On a trip to a supplier in China in
2007, the Toledo, Ohio, businessman came across a product that seemed to
fit the bill: a thin, brightly colored silicone band shaped like an
animal. It was designed for office workers, but Mr. Croak thought the
concept had much greater potential as a mass-market bracelet for
children. So, he began working on his own variation on the theme—Silly
Bandz.

The 47-year-old Mr. Croak says the product sold in dribs and drabs at
first. But he says he knew he had a hit on his hands when a store
called in late 2007 and ordered 500 packs. “Within 10 days or two weeks,
the phone started ringing off the hook,” he says.

Marketed in theme packs for under $5, the bracelets became a huge
schoolyard fad and eventually sold in the millions. To stoke interest,
Mr. Croak and his team at BCP Imports LLC kept releasing new themes,
from animals to popular cartoon characters to corporate logos.

Early on, however, BCP couldn’t keep up with demand—or answer all the
calls coming in from frantic retailers. An eight-line phone system was
hastily upgraded to 48 lines. The company’s lone server proved
inadequate after a CBS News segment on Silly Bandz led to 11 million
hits on the product website; the company now has three servers.

“It was difficult,” Mr. Croak says. “We had to figure out how to
handle all the growth. But I always tell people, if you hear me
complain, slap me.”

As
the economy crumbled in 2008, sales of Silly Bandz kept growing. At one
point, the company was so overwhelmed with shipping orders that Mr.
Croak sent out a plea for night-shift workers on Facebook. A few hours
later, a line of applicants snaked around the block. “We had to lock the
door because we had so many people show up,” Mr. Croak says.

The hiccups in logistics allowed copycat manufacturers to get a
foothold. “I don’t think the knockoffs would have really gained any
ground had the retailers not been in dire need of inventory,” Mr. Croak
says, adding that BCP is vigorous in protecting its copyrights.

Although demand is rising for Silly Bandz abroad, the product has
already peaked in the U.S. Mr. Croak says he was planning for a slowdown
a year ago, and so BCP has introduced a range of new items: the Slap
Watch, which has an oversized, brightly colored silicone wristband; Rad
Bandz, thick rubber bracelets imprinted with stylized words such as
“Drama” and “Epic Fail”; and RadRingz, a colorful, two-finger ring—Mr.
Croak calls it “half a brass knuckle”—with removable faceplates.

“The goal is to become a lifestyle brand of fun, innovative new fashion products that kids can buy for under $20,” he says.

Mr. Croak won’t disclose just how much his breakout product brings
in, except to say that the profits are in the “millions per year,” and
he’s probably set for life. What’s more, “Silly Bandz gives me the
capability to dream big and not be stifled by lack of resources.”

He says he realizes he may not ever have a hit like Silly Bandz
again. Yet he still gets a kick when he sees his products in a store,
and wants to keep the momentum going. “To me, it’s about the chase and
conquer,” he says.

Million-Dollar Baby

Michael Lerner’s journey to entrepreneurial stardom
began with a white-knuckled ride down Storrow Drive in Boston.

Mr. Lerner had agreed to drive his
18-month-old nephew home after a Sunday gathering at his parents’ house
in 1984. Childless himself, he soon realized he had failed to account
for the hell-bent traffic on Storrow, a notoriously busy expressway
along the Charles River. “People were tailgating me and cutting me off,”
he says. “For the first time, I felt like a parent feels when they have
a kid in the car.”

Soon after that nerve-wracking trip, a friend called with a tip for
Mr. Lerner, who was looking to move out of the executive-search business
and into consumer products. Two sisters wanted to sell a safety sign
for car windows; they had seen it in Europe but didn’t know how to
market it.

It was kismet. Mr. Lerner struck a licensing deal for what would
become the Baby on Board sign. “I believe things happen for a reason,”
says Mr. Lerner, now 59.

Using his contacts in the retail industry, he started pitching to big
department stores. The first month, his company, Safety 1st, sold
10,000 signs. Within nine months, it was selling 500,000 a month. “It
ramped up real fast,” he says. “Around Boston, I couldn’t go down the
street on a particular day without seeing one.”

By 1985, the first knockoffs started appearing, but Mr. Lerner had
developed strong relationships with his retailers and was able to
protect his shelf space. Sales really didn’t start to dip until the
parodies came, like “Mother-in-law in Trunk” and “Baby, I’m bored.”

“They weren’t funny at the time to me,” Mr. Lerner says. “But they really were a little funny.”

By
the start of 1986, the fad was fading. Safety 1st had already
introduced other products, including a Tot Spotter decal to help
firefighters quickly locate bedrooms where children might be sleeping.
But Mr. Lerner saw a bigger opportunity in child-safety products for the
home.

At the time, gadgets like outlet covers and drawer locks were
consigned to odd corners of hardware stores and other hard-to-find
spots. Starting in 1987, Mr. Lerner began transforming the sales niche
with more colorful packaging, new designs and lower prices. “We had a
really good, innovative team,” Mr. Lerner says. “We were very nimble.”

Safety 1st also capitalized on the rise of the big-box stores,
developing strong bonds with companies such as Toys ‘R’ Us, Wal-Mart and
Kmart. Between 1989 and 1996, sales grew to $105.8 million from $7.7
million, according to regulatory filings. By 1999, with sales at $158
million, the company began fielding buyout offers—and ultimately agreed
to be acquired by Canadian company Dorel Industries Inc. in June 2000.

It was then that Mr. Lerner got his big payday. During the Baby on
Board boom times, he says, he reinvested the profits from the product to
fund the growth of Safety 1st, so didn’t see any real money until the
sale—$38 million, according to regulatory filings. (He also sold some
shares during Safety 1st’s initial public offering.)

After the sale, Mr. Lerner spent much of the next decade traveling,
spending time with family and playing golf—which led him to his current
venture. He damaged some ligaments in his thumb, and after surgery the
digit would get inflamed after workouts or golf games. Then he started
using a therapeutic band that helped eliminate the inflammation and the
need to routinely ice the thumb.

The band worked so well that he decided to sell his own version of
it, through a Boston-area start-up called True Power. The company, which
has testimonials from several New England Patriots, claims the bands
use negative ions to speed oxygen delivery in the blood, which in turn
hastens recovery from injury and fatigue.

“I know there’s some skepticism about the product with some people,
but it really does work,” Mr. Lerner says, adding, “It’s easy to sell a
product, but it’s more meaningful to sell a product that adds value.”

Big Hair Day

May 2007 was not shaping up as a banner month
for Kelly Fitzpatrick-Bennett. Her career as a mortgage broker was on
the rocks as the California real-estate market imploded, and her first
husband had just filed for divorce. “I was sitting in my room crying,
which is unusual because I’m so optimistic,” she says.

An episode of “The Big Idea with Donny
Deutsch” popped up on the television, and Ms. Fitzpatrick-Bennett was
captivated. Mr. Deutsch talked about finding something you love to do
and using that to come up with a money-making venture. She watched the
program three nights in a row and read through a list of recommended
books on start-ups.

Ms. Fitzpatrick-Bennett, now 48, knew one thing she loved: styling
hair. She had run a small salon from 1994 to 2001, and her customers
invariably wanted their hair to appear fuller. A good stylist can bump
up hair to give it more volume, but that wasn’t an everyday option for
most of her clients. At the time, she wondered if a hair insert could
solve the problem, but never followed it up.

Now she pursued the solution with a vengeance, crafting prototypes
out of popsicle sticks, Velcro and whatever else came to hand. She used
her college-age daughter, Katherine, as a half-willing test subject.

“Growing up poor, I was a chick MacGyver,” she says. “If you didn’t have something, you make something.”

She
enlisted a design engineer to help smooth out flaws in her model, a
crescent-shaped insert that propped up teased-back hair and gave it
extra loft. Ms. Fitzpatrick-Bennett dubbed it the Bumpit, and a friend
with a plastic-injection-molding business began limited production of
the device.

She also set up a website and an office in Fresno, Calif., for her
company, which she called Big Happie Hair. Her title: chief executive
optimist.

Ms. Fitzpatrick-Bennett started going to hair-product shows, and the
response was immediate and overwhelming. “Our booth would be mobbed the
entire day,” she says.

Her friend’s manufacturing business could only provide 200 units a
week, not nearly enough to meet demand, so she found another supplier in
San Francisco. With more inventory, the company was ready for more
exposure, but Ms. Fitzpatrick-Bennett didn’t want to pay for a
professionally produced commercial. So she made a homemade one featuring
her daughter and some of her sorority sisters, who were paid $50 each
plus dinner from Panda Express.

When the ad showed up on MTV, orders came pouring in. Soon
celebrities were touting the Bumpit, including Carrie Underwood,
American Idol participants and Miss USA contestants, Ms.
Fitzpatrick-Bennett says.

Big Happie Hair’s 20-person operation found it difficult to keep up
with orders, and Ms. Fitzpatrick-Bennett realized she needed a partner
with better distribution. In 2009, she struck a deal with Allstar
Products Group, a company that licenses such products as the Snuggie
blanket, promoting them under its “As Seen on TV” brand.

Last year, though, sales started to slip, and parodies started
popping up on TV. Ms. Fitzpatrick-Bennett says she doesn’t mind the
backlash. “As long as people are talking about it, it’s good,” she says.
“Most late-night shows did spoofs, and we loved it.”

At its peak, the Bumpit sold at a clip of a million units a month.
Ms. Fitzpatrick-Bennett’s current business plan calls for sales of about
20,000 a month. “I was pretty realistic in knowing it would only have a
year of good life and then it would just sit and stop,” Ms.
Fitzpatrick-Bennett says.

With more time on her hands, Ms. Fitzpatrick-Bennett has begun to
look for bargains in rental properties and foreclosed homes. She won’t
say just how much she’s taken in from her signature product, but “she
could retire now,” she says.

Meanwhile, the money has allowed her to buy a large Tudor mansion
with four guest houses, and she drives a new Honda CRV instead of a used
car. (Some of her newfound good times aren’t tied to money, of course:
She remarried in December.)

A follow-up product to the Bumpit hasn’t fared as well as the
original, but “I would love to continue inventing other products,” Ms.
Fitzpatrick-Bennett says. “If I had a dollar for everyone who said no,
I’d be richer than I already am. When someone says no, there’s always
another avenue.”