Originally Posted by Ari Blackthorne

To tell is very easy - there are three types of payment info:

"Payment info not on file" = Unverified basic (freebie) account

"Payment info on file" = "basic' account, but payment info on record (may or may not have been used.)

"Payment info used" = Premium account.

Now, I could be wrong. However, I've found this to be pretty consistent across the board. What I mean is a basic account with 'payment info on file' always seems to say this even if they have made purchases from Linden Lab.

As for why I love this paradigm, see my blog:
no-payment-info-no-search-woot/