Followers can be easily increased if you follow some article which is related to it! I tried wordpress plugin which can increase your twitter followers day by day for this you need to read this article. But make sure you are using wordpress for this method since this plugin will only works on that.
You can still increase your twitter follower by following top influencers, targeting your competitors followers by following them too. Make sure you still create engagement with your followers.
It's just a matter of quality and interesting content. Nevertheless use some twitter marketing software like twtboardpro to manage perfectly.
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