Honestly? No, and I don't believe a lot of people who say they have because they usually quantify large follower numbers as a "good thing".
I've worked with social media accounts for some large companies, and have built large-scale Facebook pages and functionality using the Twitter API, and although we've seen some modest traffic and input it's often come at a large cost. For the time and money spent on this work, it would have probably been far better to simply use that money on advertising and marketing, and to just use the time elsewhere.
Social media is often said to be a good thing, because it takes time and people feel good when good things happen after they spend hard time at something. More often than not, what I see is artificially large numbers of users. One client viewed a recent social media campaign as a success, despite spending £6k on the campaign and only building a modest level of traffic. The reason he said it was a success was because he had gained several thousand Twitter followers and had a ton of likes on Facebook. The reality of the situation is that most of his Twitter followers are spammers, and the same for Facebook is probably true.
LinkedIn groups have worked well at times, but only as a community, and only with a LOT of work involved. In my experience there are only certain groups of people that are interested in using LinkedIn, and these are usually the middle-manager types with something to gain from using LinkedIn all the time.