I myself pondered the same question some years ago , but then I realized that the majority of "guests" are actually members whom don't care to sign in. Take myself for example, I don't have a tank running at the moment, so I browse to "stalk" some ppls threads and new info that may have become relevant in between visits. I don't need to sign in cuz I don't have much time to contribute like I did some years ago when I had a tank running and was more active in the hobby. Right now it's on the back burner in my life so I just browse the vast amount of "reef porn" on the forum as I'm sure a lot do as well lol . Another reason, is the browser settings on my phone are set so I do not remember any pw or usernames, so I just skip the sign in process when I'm here to just read and browse threads unless I need to contribute (like now). As well as I don't have a PC with internet at the moment (fried NIC card courteous of Florida's awesome lightning storms ) so I'm limited to visiting on my phone and it's just an extra step I have to do, just to read. And it's not practical in my instance. The amount of guests that aren't actually users, IMO, is probably a lot less than you're realizing. Just a lot of lazy or not very active users is my guess, remember you only need to sign in to post, some just wanna read. But it would be nice to have more active members, I'll agree with that.