Many banks are in trouble now. After the demise of Lehman Brothers, the Feds are pitching tax payers money to save AIG. Washington Mutual seem to be on its way to a new boss too. Still other banks are looking for clever ways of funding: your pockets.
One of the well-know banks (name start with a E*) is offering $10 bonus if you pitch in $5000 more into your bank account by October 15, 2008. It's probably a way to glean more cash from the public to secure their own financial position.