First time I've noticed it, I guess my adblocker isn't dealing with it anymore. (or, the ad itself has changed it's coding.)
From my initial attempts, it's an adbar that has different coding on every page. it looks a bit like this:
www.gaiaonline.com##CENTER[id="yui_patched_v3_18_1_4_1585081286270_131"]
With everything being the same up until the _1_4_, after which point the number strings vary. I think the difficulty is that specific adblocking of the first part of the code isn't specific enough, and the second part of the code changes. I am only running a basic adblocker, so while it's something I can modify, some things can easily sneak through the cracks.
humOh, I also found another one in the general forums, powered by Taboola. (that was a quick fix. but, Firework appears to be embedded into the site and not actually classified as an ad, just the things inside of it.