Amazon has spent nearly 30 years encouraging shoppers to buy directly from Amazon.com. Now, however, a new program is “extending its tentacles out to other sites,” as one analyst put it, encouraging customer purchases elsewhere.

The program offers two of the things Amazon likes most, but experts told Adweek brands will have to weigh the pros and cons of participating—and while short-term benefits to the ecommerce giant are clear, it could ultimately even place Amazon in regulators’ crosshairs.

Prime real estate

The new program, Buy with Prime, expands the well-known benefits of Prime membership to sites beyond Amazon. It will start with sellers using the Fulfillment by Amazon (FBA) service and eventually extend to merchants without an Amazon presence.

Shoppers will see the Prime logo on participating sites and be able to use the payment and shipping information stored in their Amazon accounts to place orders.

“With shoppers purchasing directly from merchants’ online stores, Buy with Prime will allow merchants to build customer relationships and brand loyalty while offering conversion-driving benefits like fast, free shipping,” said Peter Larsen, vp of Buy with Prime, in a statement.

But a simple—yet key—question remains.

What’s in it for Amazon?

First off, of course, is money.

Read it all: Inside the Grand Experiment to Expand Prime Beyond Amazon