I tried to find out how many shrines are devoted to this kami (even if she's not the only one being devoted to), but I didn't have much luck aside from finding one specific shrine that did. Another problem is that I don't know if people can offer prayers to any kami at a given shrine; and, if so, how many people pray/call upon Toyotama-hime/Otohime. When I get down to it, unlike some other kami I could name, I just have no earthly idea how "popular" she is, or how prevalent she is in people's minds.