This reminds me of the highly-untargeted spam emails that I get all the time from people asking if they can write blog posts for me. Naturally, they would contain a lot of links to some other site. The idea has definitely been done before. Think PayPerPost, SponsoredReviews, etc. Sounds like an excellent way to get yourself deranked by Google.
I've used those sites before. This seems different in that they're not gaming advertising but actually exchanging like-kind content. Google doesn't derank for that.
'highly un-targeted' is the keyword in your comment. With TrafficGun, there's no spamming ppl with unwanted requests. Every user on the platform is amenable to cross-promotion.
As for PayPerPost, SponsoredReviews etc - our focus is primarily on cross-promotions b/w bloggers who vet each other.
Finally, re:Google - We encourage all users on our platform to nofollow all links. TrafficGun isn't about SEO/links. Its about gaining real, live visitors.
Content for the sake of exchanging traffic by means of links. I'm not convinced this is much different (if any different) than what I mentioned. SponsoredReviews focuses on bloggers writing ads for products. Your idea is to have the arrangement be two-way so that both sites write about the other but then you have the issue of all these sites stacking up two-way links which looks like link exchanges. I doubt Google is going to be thrown off by the nofollow links. It's been abused to stop pagerank 'leak' to the point of losing its original meaning. I don't think emphasizing the use of nofollow is going to save anyone from Google realizing sites are putting out farm-style content.
