Its incredibly easy to make fake FB accounts these days and just based on many Disqus comment sections I have seen across the internet, I don't know that a lack of anonymity really cures bad behavior.
A more intrusive, but verifiable method may get fewer signups, but the higher intent shown by someone giving real info may mean you can avoid FB pitfalls and actually charge lower prices, while getting a richer community for matches and thus a better product.
