Reusing mugs varies from location to location. At BWV, the mug is the same as it has been for the last two years (at least). They do not tell you that it is a length-of-stay program, so we have reused ours on subsequent trips. (But, we forgot to pack them for our trip earlier this month and DW ended up buying a new one; we now have three of these.) At VB, they have a seasonal mug program, re-fillable for length of stay at the pool, Green Cabin Room, Shutters, and Sonya's. The mug itself changes from season to season, so it was different now than the one we purchased in January (which wouldn't matter anyhow, since we hadn't packed that one either). Even at $10.95, DW gets her money's worth during a single visit.
Ralph