So much is going on with ActiveRain that we often miss the obvious. Can anyone tell me what I've missed - i.e., what is the reason for bloggers making the first comment on their own blog? It's obvious why a blogger would respond to comments on the blog, but increasingly I'm seeing people make the first comment on their own blog. If it were something significant that they missed - often not the case - they could go back and edit the blog. What is the value of making the comment?

I think it's a "prime the pump" type concept. People are more likely to comment on a post when someone else has. I don't do it, but I've noticed many who have adopted the policy.
kk
Bryant, I agree it looks and feel stylistically like a P.S. No harm I'm sure, so no foul.
We've all seen the comments though that are "non member" anonymous types, now that's a bit psycho to sign off and then post a comment to make it look like you've got some attention quick!
Sharon,
Try commenting on your next couple of blogs and let us know what happens.
figGreg and Kristal - it may indeed be breaking the ice and priming the pump - though to me it seems odd to read a blogger commenting on his own blog, as opposed to replying to comments on the blog.
Bryant - you did it on your 100th featured, I just did it on my 500th blog. L'Chaim!
Steve and Michele - could well be.
Tony - OK, I did the 500th. Thanks for egging me on.
Greg - I just tried it, will let you know what happens. Christina, you, too.
Brian - ok, so I'm not as sharp as you are! I did it on the 500th, which isn't as hilarious.
Interesting point, Sharon. This has occurred to me a number of times and I am seeing it more and more regularly. I don't do it and it strikes me as a little odd. Does it make a difference? IDK. Maybe it's worth trying out.
Jeff