As the person whose throw-away remark may well have prompted this thread, I tend to agree. Yes ... why not just say 'webassist customer'?
And maybe also give the date of the purchase of their first web product? This could easily be determined from their account, and might also cover situations in which people for whatever reason, simply changed their email handle?
Or ... might it be better just to stick to the date of their first post to this forum? A person might not want to be identified, for whatever reason, on a return to posting, and if they came back with a new user name but same date for a purchase WebAssist members who were smart (might be one or two here, but you can never tell where they are hiding, sometimes!!!) could put two and two together and re-identify those who didn't want to be re-identified.
Why not just 'WebAssist Customer', date of first post, and number of total posts. All has exactly the effect intended.