How Do You Get Thousands of Followers

My husband asked me the other day, quite perplexed, how do you get so many followers on Twitter. He has a fair number for an average person who just tweets for fun. His list is about 800 strong, and I remember those days well. Once you are into Tweeting as a form of exposure and to keep in touch with fans your list will grow--it has to. I simply don't have an easy "how to" answer for accumulating thousands of followers. I don't do anything specific, I just Tweet, follow those that interest me, and follow back those that are truly pertinent. I do not follow back or initially follow anyone that doesn't have a shared interest of any type of who I don't find interesting. In other words, I don't just follow to get numbers. I never use "follow back" services. Those are just like junk mail. A really good follow list is made up of people who are interested in what you have to say. Of course, there's a responsibility there too. While some of my posts are definitely promotional, there has to be a fair number of what I would call "connection posts". If possible, more than any number of promotional posts. I can tell you that even if someone who follows me would be who I considered of the same interest, if their feed is 100% promo or links, I'm not biting. Who wants that? Keep it real and make your followers count.