Know your customer !
Focus on the area of the world you wish people to click from. Thus, if you're looking for buyers from CALGARY, don't advertise in Alabama, Vancouver or Toronto !
Know what key words people type into Google. AdWords is key word driven, thus know the top 10 key words or experiment with it !
In your case that might be: bankruptcy, divorce, distress, foreclosure,
pre-foreclosure, motivation, debt relief, help, under water, high interest rate, mortgage qualification
Have a budget .. say $1000 over 4 month. Spend $250 in month 1 and see where clicks come from .. and if weird, adjust.
Have a compelling landing page with meaningful GENUINE CONTENT for the target audience.. not just "what is your name" but list of debt relief agencies, tips on how to re-finance their home, Top 10 list of "how to reduce your debt", a list of mortgage brokers, ... !
Let the website disqualify tire-kickers. People who need what you offer will tell you who they are.
For example, in our Googe AdWord campaign, people land on our website. Lots of clicks. Good. But it costs me nothing for people to click around. I want to hear ONLY from folks that have $25,000 or more to invest in cash or RRSP. Not $12,000 .. or $5000 .. or people that love real estate only and want to do it themselves. I am looking for investors with $25,000 or more. Other folks look for people that have $60,000 or more as they need 25% down on a $240,000 home.
Know exactly what you look for. Perhaps gender is relevant. Perhaps not. Perhaps age. Perhaps marital status.
You can hire people, for a fee, too.