PPC for a free service? Stupid?

So guys I have an interesting situation. I go through the back door on my clients. Get your head out of the gutter. I'm in the short sale business in real estate which means I help people not lose their homes to,foreclosure. Most real estate pros target people in foreclosure and go through the numbers to get people to sell their homes. We know that people don't want to sell their homes until they've made the attempt to keep it through a loan modification. Nationally less than 30% get them so our business model involves helping people through the process of applying and trying to get a loan modification, knowing that 70% will not get them and helping them short sale if and when they are turned down after building a strong relationship. We've partnered with several non profit counsels who help our clients with Europe loan modifications from beginning to end. We are competing against attorneys who for the most part are ripping these people off charging them $3k-$10,000 for the same service. They absolutely DO NOT need to pay for help. That's the message we're trying to get out, which brings me to my advertising point.

If we advertise free help the right way I'm sure we can take business from these attorneys. The key is selling the value so they respect it even though it's free. In our current model we meet with 15-20 people per month and convert an average of 3 people immediately and will convert another 5-8 at different points later. Is it worth it to build a campaign promoting free service. We know 70% won't qualify giving us an opportunity to help them sale and making us a trusted resource because we do help everyone who qualifies get them for free. Or should I just run ads for short sales and forget about this side? Any advice is appreciated. We know we have something special here, it's just getting it out there with the right message. Thanks everyone