Pinterest is millions of people freely marketing consumer products to each other. The potential for both referral commissions and data mining is huge. Reddit is

Pinterest is millions of people freely marketing consumer products to each other. The potential for both referral commissions and data mining is huge. Reddit is a fancy meme and porn sharing forum (the main subreddits dwarf all the 'intellectual' ones combined), which few advertisers are interested in, and which has been unable to produce enough revenue to maintain more than a skeleton staff with self-serve ads and premium accounts.