Why don't you research the top tattoo places in the most popular city you have fans in ( look at facebook insights for your page ). Call them and tell them, you have x amount of potential customers and work out something like if they go in and say "whateveryourfanpageis" they will get a discount of some kind or free product to put on your tattoo while its healing, i'm sure the tattoo place could think of something. Figure out the price, once you do that move down to the next largest city. These numbers don't have to be that large because the traffic is targeted, so even if they get a few clients out of hundreds, they'll see it's really is working. I've seen tattoos run anywhere from $50 to $500 even more if its a multi part job, so obviously the potential of that kind of client makes it worth whatever number you might come up with.
What are you doing to send the potential buyers to them? You're reading this
https://www.facebook.com/help/352402648173466 targeting them specifically so only they see the post related to getting them in the chair, use lots of great looking example tattoos from their website, or get them to email you some if they don't have a website, which is the perfect time to find out if they even have a website and try to sell them a website, or social site services like setting up google circles, fb page, etc. if you're smart you can outsource all that stuff on the cheap and just charge the difference that you feel is worth it to you, but you get the idea, once you talk to them and get friendly you try to upsell what you can. Anyway, make posts about the great work they do, include pictures of that great work, tell them to mention the page to get whatever you worked with the tattoo shop. Of course give the name and address of the place, maybe throw in the website if they have one.
This is all just theory, so feel free to poke holes in it, twist it, spin it, actually sit down and think about it, don't just ask for help. Not very often is someone going to sit down and do it for you like i just did. This is something that if does work, and I really don't see why it wouldn't, can be applied to any number of niches that has a business attached to it.