I pretty much agree with what Bronwyn J Hansen stated although I must admit rounding up followers has never been a primary goal of mine. I've always strived to write quality hubs and offer advice on subjects that I have some expertise in. Having said that I think asking questions and responding to questions along with posting quality comments on other hubs often leads to people checking out your profile and content.
There are other people who use the strategy of following a ton of people with the hopes that those people will turn around and follow them back. I've had people "follow me" and when I clicked on their activity I can see they just started following 100 people in an hour or two. Clearly they had not read anything I'd written. Very often these people will un-follow you within a week or two.
A writer writes. You don't want to get caught up on the number of followers as much as you want to get number of views of your hubs and ad clicks for Google and Amazon. You accomplish that by writing quality hubs, promoting yourself through Facebook and Twitter as well as using optimal SEO. Best of luck!