By CAROLYN SAID, San Francisco Chronicle

At first, the California woman, who had fallen behind on her condo payments, thought the letter was a scam. "You could sell your home, owe nothing more on your mortgage and get $20,000," it proclaimed in large type.

"I almost ripped it up," she said.

Commercials aired during the big game next Sunday will work overtime to entice viewers to dish on Twitter and Facebook, zap ads with Shazam, surf corporate websites, and view and share clips on YouTube.

In a tough economy, many small businesses are struggling to get customers to pay up. Sometimes they wait weeks or months; sometimes they are unable to collect payments at all. Late or missed payments have a ripple effect as the unpaid company juggles to meet its own obligations.

How can a business get clients to pay up?

Valerie Brunmeier of San Jose, Calif., plans a festive feast for her family on Thanksgiving, but two of her sons will have to hustle off to their retail jobs at malls later that night.

"How do you relax when you know you're heading out the door at 10 p.m. or so to go to work, and work all night long?" she said.

Jean McGuinness has excellent credit, makes a good income and has never been late on a mortgage payment for the house she bought eight years ago.

SAN FRANCISCO - Jossie and Laser, 10-week-old Labrador puppies, jumped eagerly out of their cage and swarmed over the nearby humans. The pair was bred to be guide dogs for the blind and was on their way to Seoul, South Korea.

In another room down the hall, two cats meowed as they awaited their flights to rejoin their owners in Key West, Fla., and Okinawa, Japan.

EMERYVILLE, Calif. - Prefab houses aren't just for trailer parks anymore.

Two San Francisco Bay Area startups are crafting factory-built homes and rooms for the high-end market, the kind of people who want an architect-designed custom house with all the latest green features.

Working at Pinole Paws, a pet-grooming salon, gives Ajunee Mitchell, 18, lots of opportunities to play dog whisperer; she brushes, bathes and trims about eight pooches a day.

SAN FRANCISCO - Forget Hallmark. Personalized photo holiday cards are hogging all the mantel space this month. Digital photography, easy-to-use websites and advances in printing technology have fueled double-digit growth for photo cards, despite the rampant popularity of online photo sharing.

Pay homeowners to prevent them from walking away from underwater homes?

That's the business plan for a startup that has signed up hedge funds and one major bank for its services.