After many review I am writing will auto surf effect your site.
They are some thousands of website to join in auto surf.
Sites that allow traffic with frame in it , will surely effect your site, which may result to low google indexing and impressions.
Sites that allow traffic without I FRAME may be or may not effect your site SEO or any.....
Since after reviewing all auto surf's I knew, I found hit leap.com and websyndic.com are the great sites which will not effect your site and will increase your page rank surely.