I think the poster answers his own question of how twitter will make money. He says "In other words, what happens if hundreds of businesses are created using T

I think the poster answers his own question of how twitter will make money. He says "In other words, what happens if hundreds of businesses are created using Twitter’s API but the entity supporting them – Twitter – can’t make revenue or, at least, enough revenue to be viable." Why not monetize the API, and do it to the extent that heavy users pay a heavier burden. Give away some free access every month, but once an app hits some critical mass and hopefully becomes profitable, then start sharing in the money. Twitter is at the point that if it were to do this, there would be some backlash, but it certainly wouldn't be an end for them. It would just drive all the "Feeder" companies to figure out how to make money quicker.