Make sure the site allows [R] rated sites to be advertised.
Make sure someone else didn't already advertise LR there.
Preview, preview, preview your ad post before hitting post.
Some sites don't allow certain tags and some use html language rather than our BB tags, be aware and again, preview, preview, preview.
Don't be afraid to advertise on once great boards that died...people still look there.
Advertise like crazy =)