Recently the office manager of Twin Cities Siding Professionals, in Minneapolis, phoned a prospect who had talked to the company three years ago but decided not to buy. Now the prospect was interested. “I put the bid together,” says co-owner Terry Stammen, “and headed over there that afternoon.”

Marketing experts unfailingly recommend that you stay in touch with prospects, those pitched but never sold, and your actual customers. But how you do that and how often should vary by group.

Every company is different in the way it approaches staying in touch, says Sven Johnson, general manager for Rite Window, in Woburn, Mass. He suggests that companies poll customers and prospects via email to find out their preferred method of contact. Most will say email.

“You want to find the sweet spot,” Johnson says. He defines that as continuous contact, but “not to the point where they get mad because you're inundating them with messages.”

MONTHLY TAP ON THE SHOULDER Some companies do well combining the consistent messaging of a monthly email with the personal attention of a phone call or unobtrusive postcard.

For instance, when a prospect contacts Next Door & Window, in Illinois, seeking information, a packet goes out by mail, followed within 72 hours by a call from co-owner Scott Burns. That prospect's name also goes into the company database for regular email messages promoting company events, home shows, or special offers. Burns says that customizing a message gets homeowners' attention.

But for prospects who received a price but didn't buy, mail or email may not be enough. A phone call becomes essential. “Find out why they didn't buy,” says Brian Kaskavalciyan, of G4 Marketing, a Florida company with many home improvement customers. That phone call gives you an opportunity “to get another salesperson or a manager back out there.”

PERSEVERANCE PAYS Kaskavalciyan advises sitting down once a year to analyze database contacts — those who never set an appointment or who got a price but didn't buy — to determine their disposition and the best way to reach them.

Burns says that Next Door's policy is to stay in touch, which happens a few times a year, until people buy or request no further contact. Next Door generated 49% of its business from repeat and referral last year. Two prospects who contacted the company to ask that they be removed from its marketing lists ended up buying windows.