Go over to google and put in the words "buy retweets". That's really not a problem. They have full control over the accounts (via either fake signups themselves or script kiddie iStealer means), so anything like that in demand enough is probably something you can buy.
A look at the history or content of mentions is probably the best bet to detect a faked account. Still, a clever person might slip by a cursory check.
Hell there are even Chrome plugins for free that'll get you followers, retweets and likes all automatically. Twitter is a joke. Anyone that takes their user count and interactions seriously on that platform is in for a bad time.
