The difference is that NightOwl hides what they are doing in the ToS. Nowhere in the software itself or the website (exlcuding the end of the ToS) does it say what they are doing.

The (new) developers of NightOwl have to do this because they understand that most users would never willingly participate in the trade they are "offering".

Ad-supported business models don't involve deception, the users understand the website/app/whatever is funded through advertising.