The Gap has tried out a new service Visa is offering, in which text-based ads are shown to customers at the point of payment - a growing trend among both providers exploring this technology and retailers eager to use it.

In Visa’s case, the mobile service Gap piloted would send text-message offers based on spending habits when they swiped their Visa card, Ad Age explains. Users have to enroll in the retailer’s program - in this case Gap. Once they do and when the swipe their Visa card they will receive, say, a half off coupon for a particular good or service over a limited time. It can be tailored for zip codes or times of day or consumers who buy a certain amount of goods each week.

Increasingly marketers and ad tech providers are eying the purchase transaction as a viable platform on which to display an add.

Several companies including Macy's and McDonald's are experimenting with technology offered by such firms as Cardlytics, Cartera and Clovr Media that allows them to insert targeted ads into consumers' online banking statements. In this case, a consumer who uses her debit card or credit card to purchase breakfast at, say, McDonald’s might find a 10% off coupon for her next meal.

Furthermore, the user doesn’t even have to clip the coupon. A click on the link means the chain will automatically recognize the debit card the next time it is used.

Clovr Media raised $1.5 million in seed funding from Kepha Partners and CommonAngels last October for its card linked offers technology that allows advertisers to offer special discounts to consumers in the pre-purchase consideration phase along with providing an immediate reward after the product is purchased.