I don't see why it wouldn't be allowed, but I guess you wouldn't want to let it take the place of other keywords that would be necessary for searches and relevancy. If your store isn't very well known, then people may not know to type in your title in searches. BUT if your shop is really popular (and it DOES look like you're doing well!), then it would bring up your shop right away!
Good luck!!!! :) :) :)