are you specifically targeting the bitcoin crowd with nameterrific?
Domain market is extremely competitive. But for domain registrars that accept Bitcoin, I'm quite confident that NameTerrific is simply the best. That's probably why the adoption rate is quite high.
EDIT: Just to clarify, we're seeing much more credit card orders coming up recently so it seems that the market for Bitcoin is quite limited. I guess even the largest Bitcoin merchants (like WordPress) may not have a large absolute figure for Bitcoin use. However, to us, accepting Bitcoin is somehow a symbol of "geekiness" so it's a good thing to continue.