Dude...Snotknocker and EvilMax/Moeity are the freaking Solid Snakes of yard sales.
But it takes a HUGE commitment and a TON of time to score those one in a million deals I've seen them post. You can easily make a decent living I'd guess, probably at least 50K a year, by being a yard sale pro 'full time'. At least in a decent area and if you have a keen eye and broad amount of knowledge over a large variety of collectible types (i.e. you should know as much about furniture as possible...and the amount to know is ridiculous, toys, glassware, porcelain, etc.)...basically, just about everything is collectible and collected by someone out there. The key is maximizing your profit...buying stuff for the best price and finding the collector who will pay the most for it.
LA just blows...too many sales every week to cover and over way too vast an area, people thinking their garbage is worth gold, too much competition. I just stick with being a craigslist deal stalker. I just do it for my own collecting mainly and not to resell (if I come across something I already have or know I could easily make a huge profit on, then I'll bite, sure - who wouldn't), especially since there is no way that doing the yard sale hunting for profit thing could ever come close to what I make in my real work.
But I have entertained the idea of doing the yard saling/flea market thing full time, since I do enjoy the thrill of the hunt and landing an awesome deal so much. But that would only happen most likely if and when I'd be retired, or if I was so vastly wealthy that it would be foolish to work.
I'm not sure if Snotknocker and EvilMax/Moeity do this for a living, but judging by the scores they've posted here and on their site, they could definitely make good money doing it full time and just reselling on eBay or whatnot. I'm SO jealous of their scores but at the same time I do realize it's a lot of hard work, wasted time running around and going all over hoping for a good score before some competition swoops on it, all day Saturday and Sunday from WAY EARLY in the morning until you are too tired in the afternoon to continue. God bless 'em. The rates of finding a particularly good score must be something close to 1 in 50 or 100.