Well coming from a more generalized (non-adult) marketing background, as well as what experience I've gained in the adult industry, the best advice I can give you is to find out everything you can about your buyers (or at least, who you *think* your buyers are)... age, income, interests, etc... and then read the demographics of anythign you're considering advertising in very carefully.

Most of the adult rags (somewhat understandably) generally don't have much in the way of demographics, but a lot of them these days tend to skew toward older readers since many younger readers use the Internet now for their adult needs.

And you might, later on, try some experiements with off-the-wall places to advertise, where gays are likely to read but you wouldn't think at first glance... perhaps interior decorating magazines, architecture, something like that.

Also one other thing that's really important: Compare apples with apples. A magazine with a verified circulation of 100,000 that costs $2000 to advertise in is a MUCH better deal (if demographics are the same) than a magazine with an iffy circulation of 20,000 that costs $ 750 for the same sized ad. I'd prolly go with a smaller ad in a publication with higher circulation.

Hope that helps...