Sustaining an effective engagement campaign can take a surprising amount of work. You could limit yourself to following the leads from the data you collect, but following without interacting first will get you a very low follow-back ratio. More importantly, if you follow and then forget people, they may follow back, but they’ll soon forget you. A high number of followers who don’t reply to, mention or retweet your account are of no value. True engagement is long-term and repetitive.