Make sure you are ONLY following people who are related to your business market. People are more likely to follow you back if you have something in common. You can then build relationships with your followers with regular exciting posts.
I'm just going to run over a simple method. Go on a social exchange site like "YouLikeHits" and you can gain followers from there. Or Twiends is good. The downside to this is that they are not guaranteed to stay active followers, though they usually are. I'd avoid buying followers and try and target specific people who are interested in what your selling.
The answer to this is simple: 1. Tweet about things that people care about. 2. Provide people with information that they are searching for and will see value in. How? 1. Use a service like Google Trends to find out what people are searching for. 2. Find useful information on the subject and tweet about it. 3. Remember that some issues are timeless..such as weight loss, money, stress reduction, etc. What Else? 1. Keep commercial tweets to a minimum at this stage. Maintain at least a 5/1 non-promotional to promotional ratio if your main goal for now is to gain followers. 2. LEARN TO USE HASH TAGS if you don't already know. Twitter provides few ways for users to tweet to large groups. Use what's available. Find popular hash tags and then tweet to them when you have relevant AND valuable information to add to the topic.
AddSocials . com is one of the originals to get twitter followers (plus more) safely without getting banned. All users are real people not automated accounts.
Just be genuine and post interesting stuff, spamming is not good. I post a few pics etc and usually get around 10 new followers a week, does not sound like a lot but they are all real!
You can use tweepi and manageflitter tools for getting more followers. Also both tools are free of cost. Try these tools and gets more followers.
The question should be what do you want followers for. Everybody thinks that followers=money. It does if they occur naturally. If you are BUYING followers, are they really worth? Let me use an old school analogy. If someone told you that if you paid them that they would be your friend, are they actually your friend? Hell no. Could they become your friend, maybe? If you are looking to buy followers, will they buy from you? Maybe.