One of the things I plan on doing if I ever start a website is to sell advertising for revenue. The purpose of selling advertisements would be for the advertisers to gain traffic and not seo benefits. I've been doing a bit of research and some people think that using the NoFollow string will raise a red flag with Google since many people aren't aware of this concept. What do you guys think? Thanks in advance, -Digip
That's a perfectly legitimate use of rel="nofollow" so don't worry about it. You have nothing to fear (except being dropped by the advertisers if they don't approve) for doing this.
It won't raise a red flag as long as you know how to use it. google even encourages websites to use nofollow http://googleblog.blogspot.com/2005/01/preventing-comment-spam.html