I had this happen this past weekend, and didn't even realize it. That being said, after I did it has really gotten under my skin b/c The room has a queen bed and a day bed as well as a futon, so it can comfortably sleep four, which is what I indicate. However, i had it set that any guests over three would be an extra 25 dollars. Well, the purposefully booked for three guests, and then showed up with four, knowing all along that four would be there, and it was intentional to "game" the system as previous noted. It didn't occur to me. Until they left their review, didn't bother getting breakfast or using many of the extra amenities I provide, so it didnt bother me too much. However, if all four of them would have had breakfast, taken a shower and all used a bar of soap, as they could have then like he said in his review, "it was a great value!" That was when I noticed that they were supposed to pay the extra 25 dollars for four guests, but didn't make a big deal about it, and actually took off the extra fee b/c I believe that is only the second booking with four guests. The first, actually paid the 25 dollar fee, were here for five minutes, long enough to steal my WiFI router information and passwords (a completely other ordeal), and then left. Anyway, the four guests in that room is a maximum and is really meant with the idea of a couple with two small children. However, since there is no way to inforce it, and Airbnb doesn't seem to care one way or the other. I just took the extra fee for the fourth guest down. I still don't understand how if my lowest price set is 52 dollars how smart pricing books guests for an average of 42 bucks a night! Of course, their algorithim or whatever tells me to charge 12! Yeah, and why don't I just give my house away and live on the streets, as well! I mean, come on!