I'm a control freak, so I do everything myself. All my own marketing on and offline. I'm also former IT with a degree in it, so I really enjoy this stuff. I'm like a sugar addict in a candy store with site SEO, technical SEO stuff, video SEO, etc.
I've only been at this about 4 years now and really focused on it less than two years. I followed some marketing people who are focused on my industry, but didn't get results. Found this site about a year ago and have been changing up my focus based on what I'm learning here and on the aHref's blog. The hard part is adapting what I learn to something that you can't just click on and buy.
Working now on building authority blogs and working on EAT type stuff. I'm starting to see some results there. I have one blog ranking in the top 5 for three or four long tail search phrases and even #2 for a couple more. I'm seeing minimal traffic, but it's more than I typically saw in a year before! I'm a big fish in a small pond. Currently in the larger pond I want to be in, I'm ranking in the 20s and 30s, which is up from "not in the top 100" a month before. Also been able to increase my DA with competitive research into backlink profiles of my competition. I know it's a long haul game, but I'm enjoying it. Like the Project 24 guy, I do get a thrill from seeing the traffic spike. Just implemented social sharing and (moderated and spam protected) commenting for the articles.