A Genie Bra/Jack LaLanne's Power Juicer Express (make your own jokes) split infomercial replaced ET on Sinclair's Portland, ME CBS affiliate Friday night. No on-air explanation (apart from the usual stock infomercial disclaimer) whatsoever. Revenue enhancement, or severe thunderstorm related? No explanation on Facebook, either...
Simple, some infomercial distributer walked up and said "shut up and take my money!" They don't get paid for ET, they do for infomercials. Most stations will do this occasionally, balancing viewer outrage with the nice check they get.