Rick Rolled? Too bad if you haven't.
What I like about Rick Rolling is it's a meme but also an example of musical "stickiness" -- the tune, once heard, replays in your head for hours... days.. maybe even weeks. So by tricking someone into hearing it you have altered their mind for ... you know.
It's also a video by Rick Astley, who was hot-hot-hot on YouTube's progenitor, MTV, when it was the hot new thing. As such, the video is retro-geek-chic.
People send a Rick Roll by links because the "embed" function of this particular video is disabled. Usually the links don't tell you it's a Rick Roll (like the one in the first paragraph).
You are reading an innocuous-seeming blog entry, you come across a word or phrase that looks interesting, you click it, and --