Last week The Grocer revealed Sainsbury’s was leading all other supermarkets in the promotional stakes.

The statistic may have come as a surprise to some, given the raging price war between Tesco and Asda – while Sainsbury’s is of course better known for quality than price. But it’s a reflection of Sainsbury’s pledge to offer ‘Value Where It Matters’ and give shoppers savings across the board.

Today the supermarket played its trump card with a series of three-page colour ads in the national press to highlight the latest string in its bow: Feed Your Family for £50. That’s feed them for a whole week. And not just with dozens of cans of Basic baked beans.

‘Four people. One week. Only £50. How good is that?’ the ad boasted. Beating by a country mile its own Five Family Meals for £20 launched earlier this year, the new planner suggests three meals a day for a family of four for seven days.

Today, for example, it suggests jam on toast for breakfast, tuna & cucumber sandwiches for lunch, followed by a sausage, butter bean & tomato hotpot for dinner. The day’s budget is just £6.50.

The eye-catching idea potentially gives families a great base to work from if they want to cut their weekly food bill – but it’s far from perfect.

As one caller to The Grocer this morning pointed out, it doesn’t take into account drinks and snacks – the little ‘luxuries’ that aren’t really luxuries, just what most people would expect in this day and age. Furthermore, what about those families where the parents might want a bigger portion than the kids, when not everyone eats together – or those where the kids refuse to eat anything other than chicken nuggets and chips?

Obviously the JS marketing bods don’t expect every family to follow their design for life to the letter. What they hope to achieve is simply the same thing The Grocer’s promotions story revealed.

It may not be the cheapest, but families can still get plenty of bang for their buck – a notion effectively underlined by today’s marketing masterstroke.