But a New York Times profile of Uber this weekend revealed, in passing, that Unroll.me, which is owned by a company called Slice Intelligence, isn’t just in the business of tidying up customers’ inboxes. Slice makes money by scanning its users’ email for receipts, then packaging that information into intel reports on consumer habits. Uber, for example, was paying Slice to find users’ Lyft receipts, so it could see how much they were spending each month, “as a proxy for the health of Lyft’s business.”

On its website, Slice brags that it has access to 4.2 million people’s inboxes, where it quietly sits looking at receipts from “hundreds of thousands of retailers.” Many Unroll.me users have been quite upset to learn about the extent of the data collection, which the service’s CEO, Jojo Hedaya, wrote in a blog post yesterday is “heartbreaking.”

“[W]hile we try our best to be open about our business model, recent customer feedback tells me we weren’t explicit enough,” Hedaya wrote.

Source: How Did Unroll.me Get Users to Allow It to Sell Their Inbox Data?

Hint – they used some nice tricks including the “for any purpose” line…