The strategy, together with a new slogan "somerthing different", is being launched with three TV ads. They are the first to be produced by M&C Saatchi since the agency took over the £7 million account from McCann-Erickson eight months ago.
It also marks M&C Saatchi's return to supermarket advertising after its split with Sainsbury's, for which it created the "making life taste better" line.
The 20-second spots, airing nationally from next Wednesday and supported by radio work, focus on Somerfield's Saver Card.
The scheme is seen as an important part of plans to differentiate itself from its rivals, who focus on price-led marketing activity. Instead, Somerfield will promote itself as the biggest neighbourhood supermarket, highlighting its many small, but central, outlets. Nine out of ten Somerfield stores are in town centres or residential areas.
Instead of being based on points accumulated over a period of time, the Somerfield scheme allows customers to get instant rewards at the check-out. It offers members-only discounts as well as coupons tailored to individuals based on their purchasing history.
The Saver Card scheme was trailed at Somerfield stores in Wales and southern England and the company said it was confident of signing up between two and three million customers following a roll-out across its 599 stores.
Universal McCann is handling media planning and buying for the campaign, which reflects Somerfield's bid to reinforce its credentials as a retailer of fresh food, ready meals, own-brand lines and quality wines.
The Saver Card message is underlined in one ad which poses the question "How do you know what you'll want to eat in five days' time?" and features a waiter taking an exhaustive food order for a future dinner reservation.
In another, a man is cooking an omelette with ingredients that are clearly past their best. In the third, a young couple who meet for the first time while shopping, find a baby in a shopping trolley.
The three films, which attempt to tap into what Somerfield claims are changes in shopping behaviour, were written by Jerry Gallaher and Duncan Timms, and art directed by Clive Yaxley and Will Bates. Guy Manwaring directed the spots through Therapy Films.
Martin Langdon, Somerfield's head of marketing, said: "Given the positive changes happening within Somerfield, this campaign represents an exciting opportunity to encourage brand reappraisal while maintaining our focus on driving sales."
Under its executive chairman, John von Spreckelsen, Somerfield, owned by the discount supermarketer Kwik Save, has seen a significant turnaround in its fortunes.
A substantial investment in refurbishing and upgrading its stores has resulted in Somerfield's operating profits more than doubling to £17.2 million in its most recent half-year results.