Thumbtack has had a lot of success with its pay-for-lead model. Reminds me of ServiceMagic before it transitioned to HomeAdvisor with an updated business model. (More detail in the pay-per-lead space: http://pocketsuite.io/leads-online)

Thumbtack does a great job matching up the first time client with a business in a concierge-type way -- I (the homeowner) say what services I need, then a few pros can reach out with quotes and pitch themselves. I get my choice of the litter!

Some clients like that way of discovering new pros. Other clients like to browse reviews in a Yelp type structure. Other clients like the On Demand type of convenience. Other clients like to search for discounts and deals similar to Groupon.

Thumbtack has made the lead model cool again - kudos to them.