I dont remember how I got started. I either found a marked bill, stumbled across the site by accident, or read about bill tracking from somewhere.
My Wheres Willy history
2002–2007: I played this game intensively, withdrawing stacks of bills from the bank and marking everything I could get my hands on. By March 2007 I ran out of steam and retired from entering bills.
2007–2012: Every January I returned to enter $10 bills for Sawbuck month. I also entered the occasional bill at other times, like when traveling somewhere.
2012–2016: Back in the game with a two new goals: 1) Maintain my denomination/series bingo by entering and getting hits on each one of the new polymer bills, (reached on March 3, 2016) and 2) Get a 40% hit rate (reached on May 5, 2016.)
2016-present: Every January I make a brief return to enter a few $10s for Sawbuck Month. And any time a new series of bills is introduced I get them from the bank ASAP to enter on the site.
Other than that I am now officially retired from entering bills on Wheres Willy. It was fun playing for so many years.