A dating ad that popped up on Facebook the other day reminded me how some niches make a great natural fit with Facebook and others that don't.
I would guess these would do well on FB (I have no idea what FB restricts and what they don't mind you):
- dating
- tickets (I see concert tickets pop up all the time, I actually pay attention to those ads)
- jobs/job search/employment/career advancement
- education
- deals/coupons/vouchers
- cellphones/mobile
- humor sites
- non-profit/social causes