I had already been involved in SEO for 3 yrs, when in 2010 I came across Bill on Twitter. I have tweeted with him on numerous occasions and always look forward to his blog posts on upcoming patents and what they could mean about the way our wonderful world was evolving.
I actually managed to inspire a blog post (one of my proudest moment) when I tagged him in a heated debate about paid guest blogging with a mummy blogger. I even got a link back from his site! This was before I had even heard of outreach!!
Amazing chap and has definitely influenced me in SEO