What do you do to keep your customer after your deal of the day runs? That’s a big question for tens of thousands of SMBs — many of which have used deal a day as a loss leader and have an investment in making it work.

Companies such as Closely and WildFire Interactive have a number of promotional and marketing solutions at the ready to deal with this. So does Groupon, via Groupon Stores.

San Diego-based TipCity has taken its own approach. The company is set to offer subscription accounts starting at $99 per month to restaurants and bars for time-sensitive Flash deals that show up on the TipCity site, or come in via Twitter accounts or e-mail (i.e., $3 drafts for the next two hours).

Key to the company’s appeal is a self-serve paperless system where users simply mention TipCity to restaurant proprietors to receive the deal — or show their mobile. Restaurants and bars can set as many deals for as long as they like. They can also plan special promotions for events, such as Ground Hog’s Day or Valentine’s Day.

At this point, the company has 100 restaurants and bars in San Diego testing the system. On the consumer side, it has 30,000 users, many attributable to a partnership with The San Diego Union-Tribune’s SignOn San Diego, which promotes the service as part of its extensive deals platform. Five to seven deals are featured at a time.

“It’s a way to win repeat customers” and gain a strategic advantage, says CEO and founder Hiep Pham. “Groupon doesn’t bring in repeat customers.”

Under TipCity’s system, users are able to personalize the deals. They can receive every deal in the area, or they can choose which neighborhoods they are interested in (i.e., “Carlsbad,” “Encinitas, “San Marcos” and “Cardiff”). Pham adds that the deal with SignOn could be a model for working with newspapers and other local media in other markets.

So far, Pham adds that the big learning for the company, which has nine full-time employees, including two salespeople, is that e-mail, mobile and the company Web site are all roughly equal in importance for a flash platform. “Mobile is good for people who are in transit, or looking for something to eat. E-mail is better for people who want to plan ahead.”