Question: what is the bloody difference if a guest arrived at a thread you are subscribed to from a search engine or if a search engine spider is crawling a thread you are subscribed to?

If you want to see if anybody has posted to threads you're subscribed to, you can see that listing here: http://www.daniweb.com/forums/subscr...ewsubscription

But DaniWeb gets millions upon millions upon millions of visitors every month with the average thread receiving from a couple hundred to a couple thousand visitors. So how exactly does it improve your experience on DaniWeb or your interaction with the DaniWeb community by seeing that some anonymous visitor or search engine spider is currently viewing a thread that has already received hundreds of views and is destined to receive hundreds more?

To me, the main focus is seeing if and when people reply to posts in threads you're interested in ... not necessarily just viewing them. You see, posting in a thread expresses interest in the thread. Simply viewing a thread signifies nothing - they could have randomly arrived at the thread from a search engine, they could be using the 'view previous / next threads in forum' links, and they could be one of those people who clicks on 100 different threads an hour, with no interest in more than a small handful of them.

Experience. A guest may have ambled on something -- which is cool. Spiders tend to be triggered by fresh responses, so if one of them is triggered, chances are good that it is back in play.