The psycholoy of pitching the $12 as a subscription works against the majority of BF members who may only need the service once, and maybe (at most) twice in a given year, if ever. Something like a $3 - $6 'pay per ad' fee (no subscription necessary) might make someone selling a bike not feel like they are paying for an entire year for an item that might sell in far less time than that. The fee to place ads could be surcharged on the existing $12/yr subscription without raising a single eyebrow or it could be advertised as a 'free' (worth $6) benefit to subscribers ...