Here's my situation and maybe a reason why your not getting any customers maybe.....
When I started outsourcing my designs I shopped around for adult designers for a few months (about half a year).  I worked with several designers both exceptional and extremely bad!  Working with those bad seeds who didn't deliver on their designs or lowballed me on the design work, put a very bad taste in my mouth.  Once I found the few designers from months of shopping around and wasting cash on designers that couldn't deliver I have never gone anywhere else for designs.  Probably the one and only thing that would influence me to try a new designer is if they offered PROMOTIONAL deals at really cheap prices and then prove that their design work is worth my repeat business.
Otherwise, I stick with the 3 design companies I've come to respect and trust with my business.  Three design companies with three different styles is more than enough for me, and don't see why I would need to try another company.  Unless of course I needed something done really bad, and all the companies were backlogged, which is highly unlikely....
just my opinion, and view from a fellow adult webmaster..hope it helps ya...
