In the quest to produce good leads, no stone goes unturned. In coming years, one of the best sources of leads may be online scheduling (or “appointment calendars”). Former YPG executive JP Lion is working on scheduling solutions with Maxipage. Bookfresh has concentrated on scheduling as its differentiator. Now along comes Full Slate.

CEO Bill Lange says that his two-year-old online scheduling company may look like a simple utility, but it plays a much larger role. “We’re a revenue generation and business growth tool for the SMBs, resellers and partners we work with,” he says.  “Consumers want to complete the deal online, and this gets you closer to the revenue.

“In the short term, it is a huge differentiator,” adds Lange. “In a couple of years, it will be a ‘must have’ feature.”

Top categories for Full Slate have been alternative health care, message therapists, fitness centers, hair and beauty salons, pet groomers, and mental health therapists and counselors. “These people live and die by their schedules,” says Lange.

Full Slate is pursuing its customers via a number of channels, including companies that create and promote online presence, general Web site builders, vertical Web site builders, vertical directory/trade associations, city guides, Internet Yellow Pages and SMB resellers. The site has also been surprised by the high degree of organic growth it has achieved, in part by being listed by SMB sites such as GoDaddy and Web.com.

One thing it won’t try to be is a destination site.  “We are not doing that,” says Lange. “We provide the conversion element.”

The company’s business model relies on offering free trials of 10 appointments, and then converting to monthly subscription fees that typically range from $29.95 to $49.95. Pricing is generally based on the number of employee schedules are maintained.

One of the company’s newest customers is Goodtherapy.org, the No. 2 therapist site (after Psychology Today) with 3,000 mental health therapists. It sees its business doubling or tripling in 2010 and eventually working its way up toward the 600,000 practicing therapists in the U.S.

CEO Noah Rubinstein tells us that the addition of online scheduling “is something we’ve been wanting to do for a long time. Therapy is a unique service in which relationships are very important.”

Rubinstein sees the feature giving a boost to his conversion numbers, and adding value in terms of retention. “It will help lock-in members for the long term,” he says. He especially appreciates that members can access their schedule via Full Slate, GoodTherapy.org or their own site.

Full Slate CEO Bill Lange is speaking on the Tools of Marketplaces precon at Marketplaces 2010 March 22-24 in San Diego.