I have just received an M&S Sparks card in the post, went on to activate it and I have a choice of offers - 20% off womens clothes online to use today, free percy pig sweets if you spend over £15 in the food hall, free roses if you buy champagne etc - pick one.
I think you can just go into your account (or open one) and activate a sparks card even if you haven't had one posted yet.
But worth it if this is how they are going to do their offers from now on?
Obviously I now must find something to buy with my 20% code that expires today - clearly will be on a hiding to nothing!