I check my credit score for free every few months on two sites. It bounces around very oddly, only a few points up or down, at times it can't go up anyway. I don't change anything at all. I checked today and it was down 7 points, from 850 to 843. Did I do anything differently? Nope.
I didn't take out more credit, I paid down my mortgage as always, paid the car loan on time, paid all my bills as usual. It doesn't matter, but it's weird to me. And now one of them advertises some gimmick whereby you supposedly can increase your CS by clicking on something, it's not very clear, they show a lot of happy actors (duh).
My assets far outweigh the two loans I have. I got the car loan because it's 1.9% and the salesman said he would do a better price if I took out a loan.