Really disgusting behavior by Target.
This must have always been their plan, since the free shipt via visa terms always stated that the benefit had to be used via shipt, but it worked for target anyway. A great way to get people hooked into getting same day delivery and then pulling the "free" rug out from under us once they hit a certain volume.... The first taste is always free. Yuck!
I think a DDMS article is warranted. They should have converted shipt memberships, even from the visa promos, into circle 360 memberships automatically.