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Screenshots posted to Twitter by @am_Bix and at least three other Twitter users showed new evidence this week that Twitter is preparing an entry into e-commerce.

A new “payment and shipping’ option appeared in the Twitter app for Android phones, users reported. TheNextWeb verified the reports yesterday–but by today, the option had vanished from Android user settings. In any case, “payment and shipping” was never open to be activated. But the words’ quiet appearance in the app add to a growing list of evidence that Twitter is plotting an e-commerce play. Twitter might roll out its own ‘buy by tweet’ before Black Friday.

Twitter bought CardSpring, a payments infrastructure company, in July.

Rumors that Twitter has been investigating online retail have been circulating since June when media and technology news site Re/code discovered a “buy now” button lodged in tweets with links to the retail site Fancy. In January Re/code also came across documents that Twitter may be in conversation with the payments start-up Stripe. The trail of breadcrumbs pointing to Twitter’s latest venture goes back even further, to last August, when former Tickemaster CEO Nathan Hubbard was named Twitter’s new head of head of commerce.

In February, American Express launched its own “pay by tweet” feature, allowing cardholders to buy items with a hashtag.

While nothing is clear as to exactly what Twitter has planned, eMarketer estimates that $304 billion will be spent on online retail this year. Projections have U.S. retailers spending $11.2 billion on digital advertising, 37 percent of which targets mobile technology like Twitter and Facebook smart phone apps.