It’s like the most persistent sales clerk you’ve ever encountered.

Major retailers are working with a new smartphone application that tracks and offers promotions to shoppers as they move from outside the store, to counters, to cash registers — even inside the dressing room (now that’s persistence).

The app, called Shopkick, is now available on iPhone and will be available by fall for Android phones. And with five major companies supporting it — Macy’s, Best Buy, Sports Authority and American Eagle Outfitters, along with the Simon Property Group, the prominent mall operator — it is getting a big introduction.

Customers with the Shopkick app will get points (called kickbucks) for entering a store. Pick up a putter at Sports Authority, and points drop into the app. Stop in the dressing room at American Eagle, and more points arrive.

The points are redeemable for gift cards at the retailers, along with music downloads or credits toward Facebook games. It takes a lot of points, however, to earn even a $5 gift card, although the stores say they may adjust the point system to make points more valuable.

Whether shoppers will get a kick, so to speak, out of being followed — and pinged from one floor of a store to the next — remains debatable. What retailers see as sophisticated marketing, privacy advocates see as intrusive. Shopkick knows “where you are, what you buy, your spending habits, passions, excesses,” Jeffrey Chester, the executive director of the Center for Digital Democracy, said via e-mail.

Unlike apps like Foursquare, Shopkick tells retailers when users are inside, not just near, a store.

Shopkick goes further.

On Monday before the launch of application, Mr. Roeding stood on a slim strip of sidewalk on 46th Street in Manhattan, trying to avoid Times Square tourists as he demonstrated the app. As he stood a few yards from the entrance to an American Eagle Outfitters store, the app showed him all the nearby stores where he could check in — including American Eagle or the tiny candy store nearby. For each check-in — which did not require him to actually go inside — he could receive 0 to 2 points.

As per Mr. Roeding “Foot traffic is so important, Why does no one ever reward anyone for visiting a store?” By actually going inside the American Eagle store, the app told him, he could earn 35 kickbucks. The app knows someone is in a store by listening for an audio transmitter placed in each participating store; the phone’s microphone picks up the signal, which people cannot hear.

Once inside, Mr. Roeding swiped through offers: a 15 percent discount, a sale on jeans. Enter a dressing room, once a shopper tries on clothes, sales rise, retailers know and posters on the walls offer points for scanning the bar code.

“It’s the first reward programs for desired behaviors,” Mr. Roeding said.

Shopkick earns a small fee for each kickbuck a customer earns. If a customer buys something after using the app, Shopkick gets a percentage of the price.

Right now, it takes a lot of kickbucks to earn anything — a $5 gift card at American Eagle requires 1,250 kickbucks. And retailers limit the number of eligible visits each day, so someone cannot sprint in and out of Best Buy all afternoon.

Soon, the retailers would become more sophisticated, giving points or promoting items based on sex or age, where people live, how frequently they shop or their buying history.

The companies can even weave in rewards-card numbers, as Best Buy is already doing. With that, “we have the ability to target down to even an individual level,” said Mike Dupuis, the vice president for marketing and operations at American Eagle Outfitters Direct, the Web and mobile division of American Eagle.

With advent of applications like Shopkick, its only a matter of time before many such applications shall hit the market and further fine tune their settings to meet customer requirements, based on the valuable learnings from this particular experiment.

For more info. visit http://www.shopkick.com/