How the hell does this website rank so well, for so many terms?

So this site has been around for nearly 2 years and is a gambling affiliate based around sports betting apps. It's a pretty simple site but all unique content and put together pretty well. What I don't understand is how they have achieved such a huge amount of amazing rankings for so many keywords in a very competitive niche(WITH BARELY ANY LINKS!).

Using Semrush I can see the site and their individual bookies app pages rank for 1,357 organic keywords, and a lot of them are big terms like "Skybet" "StanJames" "bet365 Mobile" etc. They aren't even targeting those individual keywords, just the bookies names with "android app" or "iphone app"

They seemed to start seeing this sort of success just over 1 year ago when they went from 148 ranking terms to 500 in the space of a month! And they have kept all rankings pretty much all year except for a dip in June, what confuses me is they only have a small amount of links (pretty much non existent compared to "free bet" sites trying to rank for these kinds of terms and none that I can see coming from anywhere that would give them this sort of power in Google's eyes.

There are only two things I can see that could be helping:

1) youtube videos ranking significantly well for each of the apps on how to install them which have had quite a lot of views and link through to the relevant pages.

2) Each page shows a huge "ShareThis" count which you can see at the bottom of the page (in the 1000's for most pages) yet the pages have only been shared at most 100 times across Facebook / Twitter / G+.

Could a huge and ongoing amount of social shares across other social networking platforms be helping them in any way?

OR AM I MISSING SOMETHING? It's Driving me mad

Would really appreciate any help / ideas so I can figure this out!

You're not supposed to post people's websites. Just an FYI.

Removed the name, thanks!

Any ideas on how it's ranking though?

Yep, that site is socially active. Ton's of keep coming social signals will surely help to rank higher.

social signals, I agree with alternatesword is the key.

With the number of parameters that G takes into consideration nowadays it is very difficult to tell.

But like the others have said, I beleive backlinks from HQ social site accounts can play a fair share in ranking

Thanks for the replies, I agree about the social signals. though i've checked interaction with their FB & Twitter accounts and it's minimal. it seems to be mainly them just posting stuff and including links to the different pages every now and again... this doesn't account for the 1-5k shares that their "ShareThis" counter shows for each different pages on the website, which is the main thing I can't get my head around!