Have to be careful about creating bots.
1: Twitter is on a campaign to delete bots currently.
2: You can easily get suspended permanently for Retweeting to much.
3: You don't have to be online 24/7 or your account doesn't have to be active 24/7 the more fake you are the more you will get blocked by legit twitter account.
4: Just do as Emma said, tweet real content and the followers will follow you. Takes time and there is no easy way to get a ton of followers quickly.
I ran a 178k account all legit followers, sold it. Now within a few months I am already catching Emma and her @IloveSkypeSex account, again, for the 3rd time