This is a really cool idea. I hope it picks up traction for you. I know a lot of the people put stuff out on Pixabay not expecting to get compensated for it, but what a great way of showing them a little appreciation. Especially when they put so much heart into what they do and we take advantage of it every day. Between your other posts much more than twice a week might burn you out. You could also consider themes for example three to five of your favorite cat photos, or car photos or whatever. Might make it easier for you to sift through those 1.4 million pictures!