Amazon's new social network is looking a lot like Pinterest

Take Amazon Prime, mix it with Pinterest and add a dash of Instagram. The result is Amazon Spark , a new shopping-focused "social network" aimed at getting hardcore Amazon users to spend even more money with the e-commerce giant.

The service launched publicly on Tuesday on Amazon's iPhone app, although it's already chock full of posts, so the company has clearly been testing it for a while. It's only available to Prime members, who pay $99 a year for free shipping, streaming videos and other perks. An Android version is planned.

Like Pinterest, Spark lets users share photo-heavy posts about their interests, ideally those leading to shopping. "It's to learn more, to sell more and to connect to customers," said Bob Hetu, research director for retail at Gartner.

He noted that it's not intuitive to find Spark on the Amazon app, suggesting that the company is not pushing it hard — at least not yet.

To use it, go to the "programs and features" section on the app's menu bar. The tool will first ask you to select at least five interests. Once you do, you'll see an Instagram-like feed of photo posts bearing shopping-bag icons that enumerate how many pictured items — plus related products — you can buy on Amazon.

A cursory glance on Wednesday showed polished-looking photos of travel scenes, cosmetics and kitchen gadgets for the interests "travel," ''food" and "beauty & grooming." A user named Kassandra posted a stylized photo of a hand holding a bottle of bright red nail polish. Clicking on the photo highlights yellow dots on the purchasable items — and one tap will take you to an Amazon product page. In this case, the Smith & Cult nail polish was available for $18.

Spark has drawn comparisons to both Pinterest and Instagram, but it's unclear if it will be a threat to either. Tech companies like Amazon, however, appear increasingly fond of cloning popular apps from fast-growing startups. Facebook, for instance, has been trying to copy Snapchat one way or another since it failed to buy the youth-oriented network several years ago. Many of those efforts failed, though a Snapchat-like feature on Instagram, called Stories, has proven popular.

Hetu said it's too soon to say whether Spark will be a threat to Pinterest. But if it is, over the long term, it will be Amazon's direct connection to retail that would make the difference. Pinterest, a seven-year-old service now valued at more than $12 billion, didn't respond to a request for comment.

Representatives for Amazon did not immediately respond to messages for comment on Wednesday afternoon.