I've been collecting some win-back offers for reference, so I created a compilation of examples from Bloomingdale's, House Beautiful magazine, tru spa, Audible (an Amazon company), Vocalpoint (a Procter and Gamble program), and Liberty London.
The presentation was made using Prezi - if you have any trouble with the embedded version, you can find a copy here.
Invite emails (examples include Liberty London)
Use me, please! Twitter and Foursquare attempt to stimulate usage (customer retention emails)
Friends and Family email offers (examples include Bloomingdale's)
Scanning for trends: QR codes