I noticed on one of my quizzes that about two dozen "Guest" quizzers have taken it today. I don't suppose these Guests affect the count or are permitted to rate quizzes?

Another thing I noticed, several of these were in minutes of each other. It seems really odd that every 2-3 minutes there is a Guest taking the same quiz...

Guest plays don't count, but each play by a registered player is counted as 3 to more accurately reflect the total number of players and guests playing.

They can't rate quizzes, but can take them. If you look at the number of plays, divide it by 3, and that is how many FT members (gold AND non-gold) have played it.

If the quiz is on a somewhat specialized subject, often people interested in the subject will tell each other about it. I've had a couple of my quizzes on specific authors linked to from discussion pages about their books. And one of my Canada-specific quizzes has gotten promotion on various websites on Canada Day. Sometimes, if you have a little luck googling, you can even find out who is talking about the quiz, and introduce yourself - I did that once.

I often find that my quizzes on the Holocaust, in particular, have been played in very rapid succession by anything up to a dozen guests, sometimes even more, and I assume that a student in a group or class has suggested or recommended one or more of those quizzes to others.

I never pay attention to my guest quiz plays, but since it was mentioned, I took a peek. It seems to me that someone was given homework... To play my "Microscope parts and lenses" quiz. I saw tons of plays yesterday during a short period of time, and then nothing, and then again a ton appeared at the same time again, about 8 hours later. Seems to me a bunch of the class decided to take it before bed, and others procrastinated and did it just before they had to leave. Teacher won't be happy; they didn't score well. Haha.

This sounds likely - I've recommended my quizzes on my lecture material to my colleagues and many people enjoyed using them as an alternative source of revision. I even had one of the professors play, and he gave good reviews!

I told my teacher about that quiz when I first wrote it (had just learned about it that week). She didn't seem to care so much, but perhaps she decided to use it after all. I made it FOR HER to use, so...