* How do you plan to make money off of this? From your FAQ you appear self funded, and it doesn't look like there are any sort of fees attached.
* Since you're just starting out, there's a good chance that someone could sign up and not have anyone to do lunch with because everyone else is too far away. How will you handle this to further expansion?
The problem of signing up for lunch and not having anyone to match with is definitely something I'm trying to avoid. A couple ideas (not implemented yet) - warn people that there are very few people signed up in their area. Allow matches with 3 or 4 people (so there is not an odd man out type situation)
Is this a dating site? Nope, not really. But you may meet someone of the opposite gender! ( Unless you don't want to. )