Sainsbury's see sales surge

Better numbers from Sainsbury's: the all-important like-for-like sales climbed 2.6% in the 10 weeks up to 17 March and the UK's third biggest grocer is up-beat on the year ahead.

Sainsbury's robust results will give Tesco pause, badly roughed up in terms of sales growth, even issuing a profits warning in January. Why is Sainsbury's doing relatively well?