HelpAttack! - Always Be Giving

HelpAttack! encourages social media users to pledge to give a certain amount to their favourite charity for every tweet or Facebook update they post. HelpAttack! then sends them a reminder about how much they owe and invites them to make the donation via FirstGiving.com.

Simple and straightforward, and of course it is scaleable. But the concept doesn't feel to me as if it will generate substantial sums. There's no connection with the cause. It's another example of microdonations, and it's clearly being used by some people, so we'll see how it performs.