It’s as simple as this.
Your deeds or actions on Twitter, good or bad, will repay you in kind.
The words “What you do comes back to you” are an excellent paraphrase of what generally occurs or can occur on Twitter. “You reap what you sow.” You plant spam, then later you gather the resulting harvest of backlash, useless followers, and nothing to show for your worthless attempt at gaming the system.
The harvest that you reap depends on the kind of seeds you sow. If you sow nothing but broadcast, push style Tweets, you cannot expect to reap anything of consequential value from that.
If you retweet value, if you engage in some type of dialogue and help others, promote and encourage others efforts, then what can you expect? Value begets value.
I think you know the answer.