Board Thread:Questions and Answers/@comment-7584353-20130416081719/@comment-5706972-20130416193248

You get 1 stamp per day, and the period usually runs about 14 days. If you don't check in one day, you just get that stamp the next time you check in - it doesn't matter what day, just how many times you check in. Once you get all 10, it usually gives an MBD and coins or friendship points on days 11-14.