I'm still receiving email from folks that just realized they had not returned the levers from more than a year ago. People get busy and forget little things like this, and with no value attached, it could become an optional thing that doesn't get done.
As our market expands and more selectors are sold every year, the free lever exchange couldn't have stayed free very long. That it had remained so for so long was because of my reluctance to change to a fee based transaction, but eventually the reality of economics forced our hand.
At this point I'd consider ending the lever exchange altogether, fee based or not. The exchange places pressure on our resources, the fee we assess doesn't begin to cover it