For sure, that plays a part as well, but for those who are more discerning I think this does add to to the probability of acceptance.

LinkedIn is a tool that reveals far more information than people imagine. I recently un-connected from some old peers because we are now effectively in competition with each other, and it felt dirty seeing connection notifications for them and knowing (later confirmed), companies they were targeting, strategies they were pursuing, etc. Not only did I not want to benefit from that, in reverse I realized the same could be seen from my activities, when clients I was soliciting would connect with me on our first engagement, etc.

In the LinkedIn world, Bud Fox wouldn't have had to follow Wildman around to determine that he was interested in Anacott Steel -- he could simply watch as his M&A team connected with the Anacott Steel executive, etc.