As the owner of the company I have been approached by innumerable companies with various lead programs. Their models are essentially all the same - we'll flood you with 99%+ garbage, but somewhere in that junkheap will be a real lead. If you have time to sort through all that you're probably in the wrong business.
The best way to generate leads is to work your sphere of influence. Another is to find ways to get people to ask what you do in social situations so it won't seem like a sales pitch. And instead of telling them how great you are, tell them why you got into the business and why you chose the company. It won't seem like a sales pitch and allows you to talk about what you do after being asked.
Trulia's advertising used to be a good way to generate business, but it's become another waste of time. However, answering questions in this forum in a way that makes you stand out is a good way to pull in business.