To be honest I've never really looked closely at this part of the Facebook site (I hardly even log on any more) but out of curiosity I had a look tonight and it freaked me out. I use a personal email address for Facebook and it's not linked to my business email at all, yet scrolling down the list of people I "might know" I found upwards of 100 people who have been customers of my business over the last 12 years or so. Some of them I literally haven't heard from for 12 years, and they certainly never had my personal email address or anything that could link them to my Facebook account (FB didn't even exist back then). My Facebook account is pretty much locked up privacy wise and there is nothing about my profile pic, cover pic or anything else visible publicly which could link me to my business and there are a ton of people with the same name as me in New York. The only thing I can think of is that these customers from years ago have for some strange reason tried to find me on Facebook and a link has been made there. Or the Facebook phone app has pulled out my phone number and linked it to other people who use the FB app and still have my phone number saved in their phones after all these years. Very sneaky if so!  But man, scrolling down that list had me yelling "holy s***" over and over again. 
 
The order freaks me out as well. It's  a 100 or so ancient ex-customers I haven't heard from in years, and then the expected "friends of friends." It's like Facebook is saying "Hey, before we show you the people you'd expect to find, have a look at these people from your past who have absolutely no digital connection to anything that's linked to your Facebook account! There, that blew your mind didn't it!" 

Voodoo.

It searches for third cousins four times removed and gets anyone closer than that...in most cases.

I tend to do the opposite of what it wants me to do.... instead of adding  "People you might know"... I periodically remove people I do know.  I also go through my "friends" list and evaluate each one..... do I actually know this person in real life..... are they contributing interesting points of view in an intelligent way....... if not.....  Culling the herd. And I rarely accept friend requests from people I have never met in person anymore.

Facebook performed a valuable service for me. It let me reconnect with a whole bunch of folks I had lost touch with over the years, and then reminded me why we drifted apart in the first place. 

http://www.washingtonpost.com/news/the-intersect/wp/2015/04/02/how-facebook-knows-who-all-your-friends-are-even-better-than-you-do/
http://dataprotection.ie/documents/facebook%20report/final%20report/report.pdf
 
They get it by comparing the huge amount of information you gave them with the stuff others give them and finding points of intersection. Did you realize that you gave them access to any contact list/email address book on your computer when you signed up and permission to just go in and upload it? Did you refuse permission when they asked?
 
Facebook.
Do no good.

Hi,
 
I rarely use it and in general, I do not use any of those friendship and brouhaha sites!
 
I have never trusted their security levels, and the fact that they want more information about you. Not that I have anything to hide ... not gay ... 64 ... didn't bop the prom queen like everyone else did ... you know ... the usual fanfare!

slartabartfast
http://www.washingtonpost.com/news/the-intersect/wp/2015/04/02/how-facebook-knows-who-all-your-friends-are-even-better-than-you-do/
http://dataprotection.ie/documents/facebook%20report/final%20report/report.pdf
 
They get it by comparing the huge amount of information you gave them with the stuff others give them and finding points of intersection. Did you realize that you gave them access to any contact list/email address book on your computer when you signed up and permission to just go in and upload it? Did you refuse permission when they asked?
 
Facebook.
Do no good.

I made a point of not allowing it access to my contacts lists when I signed up.

sharke
I made a point of not allowing it access to my contacts lists when I signed up.

Good for you. Apparently some of the people you might know missed that opportunity. 

sharke
The order freaks me out as well. It's  a 100 or so ancient ex-customers I haven't heard from in years, and then the expected "friends of friends." It's like Facebook is saying "Hey, before we show you the people you'd expect to find, have a look at these people from your past who have absolutely no digital connection to anything that's linked to your Facebook account! There, that blew your mind didn't it!"

It uses every little piece of information you tell it...
 
Age, where you were born, where you went to school, where you work, what you like, where you live, what you post about, friends of friends and any history you provided of all of that (former place of employment, other places you lived, etc...).
 
Think about that for a moment... You may have worked at "company A" 10 years ago, and if "irritating customer 1" likes that company - they end up on your suggested list and worse, vice versa. The possibilities are endless as to how they can compile those lists.
 
The less you tell Facebook about yourself the better...