The move follows a trial of free Wi-Fi in four stores across the UK, which began in July, although at the time Tesco did not reveal the locations of the supermarkets participating in the trial. Tesco said they had received "lots of positive feedback", which led to the national roll-out with customers using it to read reviews and compare prices while they shop.
Take it while you can get it, but as ever, watch the security aspect.
Tesco is one company that always brings the tin foil hat wearer out in me . Tesco really do like data. I'm wondering what data they may be able to gather using this. There are a lot of things Tesco do that we all know about such as targeted advertising through their loyalty card (club card) they also do quite a lot of spooky things such as monitoring your route through the store using position sensors on trolleys (sonitron).