Target, one of the world’s biggest retailers, has announced that it will start rolling out beacon technology in 50 stores nationwide. The devices transmit information about deals and recommendations directly to customers’ iPhones via Bluetooth, which appear as push notifications or in-app updates.

In order to use the service, shoppers have to opt-in and agree to receive the notifications on the latest version of Target’s app. The company says that it will limit these notifications to two per shopping trip, so as not to overwhelm customers with alerts.

“We’re excited to start using beacon technology to offer real-time, relevant content and services that can help make shopping at Target easier and more fun,” said Target’s president of online and mobile, Jason Goldberger, in a blog post. “This is another way Target is bridging mobile and stores, and using digital to enhance the in-store shopping experience. We look forward to seeing how our guests respond to what we’ve built.”

The technology is being rolled out in 50 stores, in Chicago, Denver, Minneapolis, New York City, Pittsburgh, Portland, San Francisco and Seattle. The retailer says it plans to use the feedback from this initial deployment to “enhance and adapt” the service before it expands to more locations later this year.

Target said it is working on implementing additional features using the technology, such as enabling a customer to call for a store employee via the app and shopping lists which can reorganize themselves based on a user's location.

A number of other companies have already begun testing the beacon technology; Macy’s, GameStop, and McDonald’s are all experimenting with the devices, and real estate developer Simon said it is deploying beacons in nearly 240 malls and shopping centers.

Currently, the technology only works with the iPhone version of the app, although Android support is in the works.