Via Dave Farber’s IP list:
[T]he CEO of Compete Inc. revealed that ISPs happily sell clickstream data — and that it’s a big business. They don’t sell your name — just your clicks — but the clicks are tied to you as a specific user (User 1, User 2, etc.).
How much are your clicks worth? About 40 cents a month per user (per customer)… and the Compete CEO estimates that there are 10-12 big buyers of this data. In other words, your ISP is probably making about $5 a month ($60 a year) off your clickstreams.
This is news to me, and I like to think of myself as someone who pays attention to these things. More here.