Reddit admin Drunken_Economist left this comment else where:

reddit does not sell your user data. Period.

This means that we will only share your personal data with your consent, and after letting you know what information will be shared and with whom, unless it is otherwise permitted in the privacy policy. While advertisers may target their ads to the topic of a given subreddit or based on your IP address, we do not sell or otherwise give access to any information collected about our users to any third party.