What makes a photo popular?

Dome of Central Christian
Originally uploaded by Cyndiva.

I love this shot - I took it at last year's Christmas Concert series. This is the same church in which we sang this year. Suddenly this pic has shot to the top of my Interestingness stack in Flickr, making me wonder what it is about some photos that attracts random traffic and what it is about others that gets them missed completely? Aside from composition/technical merit, I mean - I know there are some pics that I've taken that just aren't that good, but there are lots of stunners in my collection and this one suddenly shot to a minor bit of fame. Ah well. :D

Off to get a massage - y'all hold down the fort.