This sounds like the kind of thing where they will put up enough inconveniences to people who merely want the $50 so that enough of them will give up in trying to get it.

And in this case, you are wrong. Sometimes a free lunch is a free lunch. And sometimes you can get paid $15/hour to work part-time from the convenience of your home with no catch. Two very real companies (one publicly traded on NASDAQ) hire for these very real positions.

http://www.lionbridge.com/lionbridge/en-US/company/web-site/internet-assessors.htm

http://www.leapforceathome.com/qrp/public/jobs/list;jsessionid=3FD3AD716E1CDBE18B1C6ECEDFB7820A.lf-prod-03-2209

Just because something pattern matches as a scam doesn't make it a scam.

And if they expect to profit from it, on average, why should I extend them $50 of credit for 50 days, which is what I'm doing when I donate $50 in anticipation of ING "paying me back"?

Can't you donate $47.50 to SIAI and keep the extra money to pay yourself back for interest?