The work aims to attract existing shoppers and card-holders to the loyalty scheme that earns the user points to redeem on M&S products.
The & More card replaces the high-street retailer's traditional charge card as part of a rebranding of M&S's financial services offer, to be called Marks & Spencer Money.
The 40-second execution, which breaks this week and will run for a month, is composed of a series of people using their cards in different locations while imagining how they will treat themselves with the points they receive.
Their daydreams are delivered to the tune of the Dean Martin song That's Amore.
One young woman in an M&S store thinks of "sushi rolls, faux-fur throws and Swiss cheese with holes". Another, eating lunch, flirts with an Italian waiter and dreams of "sexy lace lingerie that will lead him astray".
Each shopper ends with the line: "That's amore."
The voiceover states: "The new credit card from Marks & Spencer. Use & More everywhere and earn reward points to treat yourself at Marks & Spencer."
The ad was art directed by Chris Hodgkiss, written by Pip Bishop and directed by Carl Prechezer through 2am Films.
James Murphy, the managing director at RKCR/Y&R, said: "This is all about & More users being able to reward themselves on products and treats they love at Marks & Spencer - the That's Amore song communicates their enthusiasm and is a strong branding device."
ABC1 housewives are the main target audience for the ad, which will appear during peak-viewing programmes such as Coronation Street and Heartbeat.
The execution will be supported by interactive activity on Channel 4.
Nick Bowyer, the head of marketing for Marks & Spencer Money, said: "The combination of fun, wit, sex appeal, engagement and trust are precisely what we hope to get across with this film."