Its actually a struggle sometimes trying to read as fast as possible, and recently I came across an advert on Quora that talks about using an App to read four books in a day. I don’t know if anyone has tried that.
There are certainly a lot of companies like that. What a shame greed is so widespread. I had no idea it was such a part of so many people when I was young, but now, wow, it never stops.
I've read four books in a day, speed reading, not something I'd do with fiction, but to get information, yes, especially if some parts I can scan especially quickly.
Its really not possible to read four books in a day, I guess the AD you saw came from a company that was concerned about making sales without any guaranteed result.