Just thought everyone should probably be aware that StumbleUpon does not permit the blatant practice of reciprocal reviewing or stumbling:
" The practice of sending PM’s encouraging or inviting other stumblers to rate/review sites in exchange for reciprocal reviews/ratings, monetary, or any other form of reward is strictly forbidden.
The practice of actively soliciting a rating or review for a site is also forbidden. Accounts participating in such practices will be deleted and banned, and the related sites deleted and banned from the system."
Source:
www.stumbleupon.com/help.html#incentive_pms
Not to be a killjoy here but just a friendly note for those who might not know