Setup the store/www server to accept any subdomain and then put your catchall A record in. Done.

Downvotes? For a suggestion that will save this person time and money since they seem to think they need more resources to redirect requests which is inferior and will length time from request to content anyway?

The voting on HN is just crap lately. This is third time in as many days that I've been downvoted for accurate technical information. I'm frankly growing weary of it.