I signed up for Dynadot a few days ago but I've read quite a few great reviews on your services at NamePros. Your user interface is simple and allows features many of the others don't (such as setting default name servers, multiple domain contacts, etc). I'm also impressed that all of your services are cross browser/platform compatible.
Keep up the good work and remember customer service is what keeps customers (my previous registrar had the most horrendous customer service I have ever experienced). I hope to be with you for many years to come.