We recently tested the impact of Twitter profile description on following rates. At some point we changed our bio on Twitter and included specific keywords that we suspected will increase the number of followers. Then later we changed back our profile on Twitter and number of followers moved back to where it was initialy.
Now I will explain what we used and what happen. But first take a look in the graph below from Twitter Analytics which shows the number of our followers over that period of time (last 28 days).
As you may be falimiar with Follow for Follow, or Followback when people follow and expect followback. We changed our description mentioning that we follow back, and if you need more followers - follow us. We also added few hashtags like #FF #FollowBack, #Follow4Follow. At this point we observed increase in number of followers. Some we also tweeting to us asking for follow back. We let this go for some time and then changed back our description to what it was before. This is when we started loosing our followers, or in fact we had more unfollowers rather then followers.
Why we started to loose our followers? The answer is that followers we gained during that period of time were strickly for following back. If we no follow back, they unfollow us a week later.
In our case we are not realy concerned because these followers are not important for us, they follow us in a hope to get follow back. They are not reading our content, all they need is us to follow them back.
If all you need is just numbers, i.e. more Twitter followers, whatever we just explained will work for you. All you need is making sure you follow them back. You may use this approach to drive some traffic to your website by using Twitter Auto DM to a new followers.
You should expect there is no quality, but you get the numbers.