You've posed an interesting question. It's caused me to realize that I've never changed my avatar since I've been here (other than from the I'm New logo) and makes me wonder if this somehow speaks to my mood, personality, or just my stunning good gargoylesque looks.
I never changed my Facebook photo for the entirety of my time there, either. Until this last week when I changed it to the equal sign as a symbolic stand of support for marriage equality. Now, I miss my old Facebook pic, so I should change my shot here and put up the one I took down from there.
Thank you for being an instrument of change.
Fport, if I may offer a well-intentioned criticism, I'd say your question is potentially unanswerable by any-and-all of the options in the poll. A person might agree with any one-or-more of those responses, yet still not feel as though they are answering the yes-or-no question you've posed.
For example:
It's very facebooky and allows me to change my mood.
Let's say I agree with this, but I also think avatars are not "important." I could feel that something's facebookyness and mood-mutabilty do not cause its importance to accrue. Do I vote for this option anyway? Do I pass on the poll entirely because the answer I wish to give is not an option? Do I choose the "useless poll" option even though I feel that one the responses accurately summarizes at least a portion of my many feelings on the subject of avatars?
[I don't care enough to write all this, but I did write all this. Is that possible? Yes, for I am a writer.]
Avatars make a quick way to recognize people on the site. They're more easily distinguished than the light, reddish username. (Ya know, I should probably get back to the optometrist here at some point!)
Personally, I go for abstract avatars rather than my own boring mug.
