All the followers followed me within 48 hours, within a week or two, all were banned.
All the retweets did nothing for my "organic" retweets, it provided no new coverage, since the account who retweeted it, only had fake followers, so nothing really happened.
I did use ads.twitter.com and that didn't really do much, but I'd say it did better for bang-for-buck.
Within three months I had 13k
Within a year I had about 2k
It hovered around there.
On facebook I bought 3k likes for around $30
I still have 1k likes for that page.
Basically, the only reason I have read that you would want to buy followers is that it can help boost your SEO ranking. It will not last long though and I bet the big social media companies start monitoring for it happening to your account/page if they detect abuse.
The conversation pretty much stops after I indicate we are happy with the award and the nomination, but will not buy any advertising with them. Funny thing is: a few weeks later some of the vendors in the space will show of their new award of place on the Top X list on their LinkedIn pages :)