To launch their new pret card (where you put money on the card so you don't have to "fumble around for change when you want a coffee )Pret are giving you £2.10 worth of free credit when you pick up a card and register it online.
"Pick up a free 'Pret Card' from the counter of any Pret a Manger, register that card online on the Pret website and it will automatically get charged up with the price of a coffee, for free! The card will be charged to the value of £2.10, so you can have any hot drink up to that amount (the 'Double Hit' coffees cost a bit more so you won't be able to get these ones totally free). Make sure you claim your free coffee within three months of registering the card or the value will expire.
Pick up your free card in your nearest Pret a Manger.