Hi Sam,
It took about two months for me to make my first sale. I guess it took that long to promote enough, and to get out there and sufficiently network. From what I can tell, it takes most shops about that long to make a sale. But after the first few sales, and positive feedback, I think people are more willing to buy from a store because it has "experience."
But stay positive, and keep on promoting. Join teams, create treasuries, and use all the other promotion sites out there to advertise (facebook, stumbleupon, etc.). I'm still working on that last one -- I still find the idea of promoting too much outside of etsy a little intimidating. Baby steps, I guess :)
Good luck! I wish you many sales!
Katherine