Slightly off topic for this post. The features of unroll.me look appealing, and would save a lot of time and frustration for many people. But what is unroll.me'

Slightly off topic for this post. The features of unroll.me look appealing, and would save a lot of time and frustration for many people. But what is unroll.me's business model? I don't see any pricing mentioned on the site. I presume this is one more service that's "free" to gain a good customer base. Considering that unroll.me was bought by Slice (slice.com) a year ago, which is related to tracking stuff you buy online and is in turn owned by Rakuten, this looks like a web of services that can gain a lot from your use of them. Most (not all) email subscriptions are a result of financial transactions like purchases. I value my privacy, and even though I know that providers like Gmail or Yahoo or Microsoft use automated systems to read my mails with such transactions, I'm just limited to trusting them (and their employees and their policies). By giving access to other companies to my mailbox with valuable information, I would just be increasing my exposure further. When companies start providing services "for free" in exchange for access to your personal information, habits and actions, it always looks very uncomfortable.