My first question is can I map my own domain name onto it?
(Yes, for a small monthly fee of $3.99 with a few other features as well.)

I particularly like the fact that one can start testing out the service without even providing an email, creating a password, etc. You can just start it up and kick the tires a bit without even having an account. Very clever and something that has been discussed as UI more services should offer.

My browser still remembers my accountless test post from over a month ago

The other bit of functionality I always look for on services like these is the ability to export data to other platforms. That is also usually a positive signal on behalf of the creators who may be charging for services.