I wasn't favourably impressed by Tom Scioli's work the first time I saw it, around the time Godland first began, but after reading the first issue of that series for free online, I decided to give it a shot and ended up enjoying it quite a bit. Scioli's modus operandi of riffing off certain elements of Kirby's style can be effective within its narrow limits once you get used to it. I'll definitely take a look at American Barbarian. Opus-8 back-issues I've found hard to track down.
I also read the first issue of Bulletproof Coffin online for free and liked it enough to go out and get the first trade, though I haven't read it yet. So these free online issues are a great way to attract potential new readers, IMO - at least, I most likely never would have become a follower of those two series without them.