I've seen a lot of discussion recently about Twitter and how easy it is to spam your followers. This is a very hot topic and many people feel very strongly about it. Some feel that Twitter is a broadcast program and a lot of promotion is normal and encouraged. Others say it is social media and that promotion is a huge turn-off.
I fall somewhere in the middle, but closer to the turn-off side. I am perfectly ok with someone promoting their books once in awhile, or posting a link to their newest blog or a cool contest they've seen or are part of. How else am I going to know about those things if you don't post them on occasion? However, I also think writers should adhere to the "passive promotion" philosophy I've discussed. Twitter use falls into that category.
The easiest way to alienate someone on Twitter (especially me) is to only promote your books. If every tweet I see from you is about your latest and greatest, I'm going to grow bored very quickly and unfollow. I don't want to see six tweets a day about that 5-star review you got three months ago. I simply do not care. In fact, it makes me want not to read your books just to spite you. That may seem petty, but it's true.
So how do you promote yourself without being annoying? Be a real person. Engage with others, post interesting articles and other information that doesn't relate to you or your books, just be real. Unless you're already on par with Charlaine Harris and Jim Butcher, you can't get away with being an elitist. Sorry, but you're just not that cool. Your readers want to be able to relate to you and Twitter is a great way to interact with them. Twitter is an even better way to interact with potential readers. Just recently, someone I chatted with on Twitter decided to read my books. And she liked them and shared them with her friends. I gained readers, simply by being me.
I also hate it (and I mean I really, truly hate it) when I follow someone and the first interaction we have is a DM from them telling me to buy their books. Sometimes, I'll be annoyed enough to unfollow right then. It is simply not ok to assault my DM box like that. There is a very good chance I will never buy your book, because you've shown yourself as being obnoxious. I don't want to support obnoxious people when there are plenty of really interesting, unpushy people out there.
I want to mention one more thing: Follow Friday (#FF) and Writer Wednesday (#WW). Simply posting lists of people will get you nowhere. There is absolutely no reason for anyone to click on those people and follow them. You need to give valid reasons and limit it to a few people a week. If you want to gain your Twitter buddies followers, you need to tell people WHY they should be followed and not just toss lists of names at them. Those people who post half a dozen #FF lists annoy the heck out of me.
One last note to leave you with: Don't follow anyone you don't want to. Twitter isn't a "I'll follow you if you follow me" venue, despite what many people think. It is a way for you to follow people you find interesting. You should not in any way, shape, or form feel obligated to follow someone just because they followed you. And those who unfollow anyone who doesn't follow them... well, more power to them. It's their choice, but they're losing out on valuable streams of information over pettiness.