

Ask HN: How does LinkedIn know so much about me? - MrSteve1212

So browsing through my linked in account, it does a great job of recommending people I know (people I graduated with ... people from work, etc).<p>Here's the thing though, it's <i>too</i> good.  For example, it just recommended I connect with a SCUBA instructor I met with once in Florida.  I saw this guy once, 2 years ago, haven't seen him since and have no other connections to him.  The only way I can figure this out is if they somehow have access to my gmail account.  I'm fairly certain I never connected gmail to linked inn, and even if someone did, surely they don't have permission to parse their entire e-mail history...<p>How do they know so much?
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highlander
Is it possible that he gave LinkedIn access to his email account and he has
your address in his email? Alternatively, could he have viewed your LinkedIn
page? Maybe LinkedIn recommend connections that way also.

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MrSteve1212
I doubt he viewed my page (I was a random customer from years ago), but the
fact that he might have connected his e-mail account sounds plausible.

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joezydeco
LinkedIn is definitely doing something with your searches. I've searched for
old high school/college friends (sure, ex-girlfriends too, you got me), only
to have them pop up in the recommendation box a few months later.

Who's to say that LinkedIn isn't adding those people to some secondary network
for you and later making recommendations off the people _they_ are searching
for?

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bartonfink
On the flip side, I'd like to know how they seem to consistently miss one of
the most important pieces of information about my career: I'm leaving the U.S.
soon. I'm planning to emigrate in the next three years, either to Australia or
New Zealand. I've made a few LinkedIn connections with folks there (hi, Duncan
and Steve!). I've joined LinkedIn groups for software professionals in both
countries. I subscribe to Google Groups for the same purpose. I regularly
search LinkedIn's company listings for software companies in both countries
that I'd like to keep my eye on. I have literally come right out and told them
this in feedback about their apps.

LinkedIn has access to all of this data about me that really should be setting
off alarm bells in their recommendation systems, and yet it's not happening.
I'm constantly given recommendations for companies, groups and jobs I might be
interested in in various areas of the U.S., and none of them take that fact
into consideration.

How can they miss this?

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revorad
Sounds like they have developed tech similar to Katango -
[http://www.building43.com/videos/2011/07/12/katango-
organizi...](http://www.building43.com/videos/2011/07/12/katango-organizing-
your-social-network/)

And now Google probably also knows that much about you because they bought
Katango.

LinkedIn also bought Rapportive recently, so they have a very high quality
people database.

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relaunched
I have similar concerns. A referral from a friend of a friend, led to an email
exchange...and nothing ever came of it. However, 2 years later, the guy is a
suggested connection on linkedin.

Highlander is probably right. I doubt there is an instance where major
providers are exchanging information behind closed doors. But if there is, it
won't be long before it comes into the light of day.

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joelmaat
I've noticed the same thing. How could they possible know that I know _of_
these people I see. Perhaps they do look at who I view, and who views me.

Its quite disturbing, but at the same time fairly impressive. I'm very
curious.

