If you're trying to grow your following on Twitter, there are several things you can do. There are some universal strategies that tend to work, and some ideas that may only work for some people. At the end of the day, I think the most important thing you can offer a potential follower is VALUE. With that in mind, here are some things I think Twitter accounts can reduce in order to be more valuable.
Automatically Generated Messages
There is nothing more robotic and anti-personal that an automatic message that gets triggered after you follow someone. This is especially true if it's some sort of pitch to buy, visit or follow something. This has been around so long it's obvious when it's done. At least try to fool somebody!
One tip-off is usually that it doesn't address someone by name. If you're going to send a message, please do that. Show that you care, and you're making a genuine attempt to connect or start a conversation. If this is truly SOCIAL media, let's not make an algorithm do all of the communicating for us.
Twitter Feeds That Feature Nothing But Posts and Promotion
Look, I understand that promotion and sharing content is part of what makes your account valuable. However, can you show us there is a human behind the account from time to time? I think it's a much better representation of your presence if I see you tweet to someone, tweet something original or even reply to someone on a regular basis. It just looks like your Twitter feed is more than just a posting service.
Twitter Feeds That Feature a Bombardment of Promotion
Again, it's social media, and therefore people aren't there to be hammered with sales pitches or self-promotion. I think it's better to pick your spots after you've spent 90 percent of your time sharing other content of value AND interacting with other people. It's all about being a little less "look at me" and a little more "engage with me".
Now, I realize someone could say, "Hey, Scott...I have 2 bazillion followers! What do you know?" I would say there are plenty of films that made a lot of money at the box office, but it doesn't mean it was an awesome movie. I'm not suggesting what you're doing is wrong, I just think you could add even more value with a couple of tweaks.