fyi most of the major marketing automation platforms already let you do this. They're based upon a peer-to-peer exchange of lead information (i.e you identify yourself to one site and they'll sell that information to other sites in exchange for identifying information about other users), hence it's already far more accurate than public registrar information.
I do realise that lead information is sold, and I've had enough offers to sell my own users (which I've declined) to realise just how prevalent the practise is.
LinkedIn sell a fairly complete business dataset. My point is that a lot of people might imagine they could do this, but probably don't really believe that they are doing this.
Then when you add in Intro's almost constant tracking (vs occasionally accessing one of the sites that sells your data - or LinkedIn on the web) it is easy to see just how complete one would be making that dataset.
I'd say that most people don't really understand believe that this happens and how good (if that's the word) that dataset already is.
Citation needed. There's no reference anywhere on LinkedIn's site to selling data sets at all. The only thing they sell are subscriptions to their site and there's nothing anywhere that indicates any of those include any kind of this data.
Looking at their live demo it looks like you just sign-in with the linkedin auth and they use the regular LinkedIn API to enrich people information, so it's not anything the average user can't access via Linkedin anyway.
I think I'm confused as to what, exactly, they do that you're objecting to.
Some time ago on HN I remember reading about a company that embeds forms on websites. So if I filled out a contact form on Site A, the third party collects the information, stores a cookie on my computer. Then when I visit Site B, the cookie uniquely identifies me, and the third party company gives my email address to Site B, even though I didn't fill out a form.