There are two ways for users to get the free currency, and both involve taking your extra loose change to a nearby CoinStar machine coin-counting machine. Just changing your coins for a cash voucher nets you 10 free Facebook Credits, but using those proceeds to buy Facebook Credits directly from Rixty gets you a bonus of up to seven percent of your purchase. That bonus maxes out at a $150 purchase (and 105 Facebook Credits) so don't even think about converting your entire savings account into Facebook Credits (via Rixty) and making a tidy 7% profit on the transaction, because we thought of it first and it won't work.
The offer, which started yesterday, runs until Sept. 7, so start smashing open those piggy banks. And remember, a penny saved is a penny earned only under very specific circumstances.