If attention bonds can be sold, why can't we build attention exchange?

From google to facebook to apple to amazon, the key barrier to entry is not the technology but the attention. MarketAmerica is good in that way and is promising in the long run. I am thinking of joining/taking advantage of opportunity where attention can meet information need:

1. Everyone needs information (He needs to get information with both money and attention (his own time)).
2. Everyone has only limited attention.
3. Everyone has limited money (production) to purchase information.

A google/media company like NYTimes or ehow.com are basically giving away information to get the attention (all advertising and branding campaign work that way.) However, nowadays, every new company is struggling to sustain people’s attention especially with limited marketing budget.

See more progress on: Attention economy