I have been both a follower (feeling like I am being protected) and a victim of WOT.
I am a domainer, and invariably WOT red cards any site that I put up, wether the site is merely informational, declaring that 'we are coming soon.' or just launched, it seems to get socked with ratings that are without comments. Not once have I had any spyware, hooks, or even allowed memberships to these sites. Hence, they are 'do no harm entities' that are usually in the process of being fully built.
My observation is that WOT cross sells 'internet safety products' to nervous web surfers.