highly addictive and loads of fun, especially when your bills go to far away places. just mark all the bills you can (dont forget to enter them on the site)and eventually you will start getting hits on them. mark them and get rid of them. I have been trading them for unmarked ones whenever i can. I get 5's from the bank, mark them and trade them for larger bills at the stores around here. them I take the larger ones back to the bank and start all over again!