Many people post in a thread and then import them right from that thread but so many people forget or don't want to take the time to add them to the database so I am often scanning threads in all kinds of forums and importing images. I have been doing that since Dave first added that function.
This is such a nice feature you added Dave! I just saw one post where one of the photos was linked and it was set right in the middle of two other unlinked photos which I had never seen before. When we added the db_photo tag before it always set it to the far left.