Sometimes not-free is an attention-earning strategy, too. For recruiters, the appeal of theladders is tied to the fact that they charge candidates a small membership fee. $30 is enough to ensure that every candidate there is serious. The guys at bountyjobs use a small ‘take a flier’ fee to ensure that headhunters who aren’t engaged in a search have enough skin in the game to avoid spamming.
Free gets attention one way. Not-free gets attention another way. Money talks. A smart marketer can use it to say “I’m serious”.