What is and isn't bird dogging ?

[Stephen S.]

People have brought me real estate deals for many years. Some I bought, some I didn't buy, and some I paid a finder's fee - I thought of it as a huge tip for a great service. On BP I read that this practice - telling someone about a property they may want to buy is illegal. OK; so what can be done legally? Is it the doing or the being paid for doing that is illegal?

Also: how about if someone brought me a property and I gave them equity in it instead of paid them cash - is that illegal? Actually that seems like it might be a better arrangement all around than just: Here's a grand - thanks.

What is the legal / illegal line for non-Realtors?