Maybe now with the new evidence of Google punishing link sellers we can get a large scale movement towards content blended paid links; something that has been an uphill battle so far. Here’s a list of basic rules to live by when selling links.
Do not talk about selling links.
I have come across a large number of websites that openly advertise you can buy a link on their site. This is a big no-no. If you have an advertising page on your site, do not list anything about plain text paid links even if it is an option.
You DO NOT talk about selling links.