I'll just weigh in here: the blog's success was very influential in accelerating the growth. But had I been a smaller blog, I likely would have had similar success in convincing the other blogs that this platform helped solve a problem they were all facing.
What I take away as important is that I was part of the problem I was solving, rather than an outsider observing. A blog with 5,000 followers is just as likely to understand that problem as a blog with 100,000 followers.
Because I was part of the problem, I was able to build a system that effectively solved it. Today, there are more than 200 blogs/channels using SubmitHub to receive their submissions -- and that happened in less than 10 months. The vast majority of them aren't there because Indie Shuffle did well; they're there because SubmitHub makes their lives better.