Having had a lifelong fascination with, and attraction to, male genitalia it was only natural that once I stumbled on this site I would stick around. But I am equally fascinated with the vast diversity in human personalities and experiences. So to have a site that explores our human diversity with an emphasis on penis is just too cool! And, though I am no size queen myself, when all else is equal size is nice so the site's emphasis on LARGE is also cool.
In my experience men are far more into the visual aspects of sex than are women. The few women I have personally known (including in the Biblical sense) who were really into sexual and phallic imagery have been a real turn on for me and this site seems to have a higher percentage of those women than the general population. I have had some very rewarding and revealing correspondences with the women of LPSG and I value that highly, they have taught me much.
And, of course, being something of an exhibitionist I totally enjoy the opportunity to show off my wares and receive others' feedback, be it good or bad. The thirteen thousand plus visits to my profile, hundreds of laudatory profile and photo comments and countless private messages I've received have all been a real boost to an old man's morale. I can't thank those who have responded in such fashion enough.
And, (like many before me in this thread) I am really impressed with the site's design and execution. It's easy to navigate, the features all make sense and the people behind the scenes are doing a good job.