I am by no means a twitter expert. But, if you're impressed by numbers and some people are, followers can be purchased. I knew a camgirl who bought 5,000 followers shortly after she opened her twitter account... thinking this would speed up her natural "organic" growth. It probably did, but I can't say for sure as she's no longer active. While I was still in touch with her, her growth seemed far better than mine. Enjoying a growth spurt is the only benefit I can see to buying followers, but maybe there are others.
I know a lot girls swear by the effectiveness of posting on Twitter. For the most part, I'm not that active on Twitter these days, but then, I'm not that active as a camgirl either. I have used twitter to promote several ventures I've been involved in over the years. I've had varying degrees of success with it. You mentioned you had about 7,000 followers. In some areas of business, that would be a very respectable following. Not so if you're a politician or a celebrity. But, excellent if you're a dog walker.
In my experience with Twitter, it comes down to the old quantity vs. quality comparison. As a camgirl, finding quality followers who might turn into customers or be customers was more than challenging. Most of my followers were other girls or people who saw me as a potential customer or whose motivations to follow were unclear. My policy was to follow people who followed me. All that I got from some of them were nasty pics with no call to action such as joining a website or following a link. Their tweets were pointless as far as I could see, and that kept me from taking Twitter too seriously.