Like chuckfinley says. If you're building a voice or are a recognised voice in any industry people will come to know you by your avatar. If you suddenly change it they might not recognise your content any more. I've been thinking for a while that I need to edit a new photo as my avatar is a few years old now - to remain consistent I need those cherry bakewells on my eyes.
What jonbey says is important too. People change. If your avatar is years out of date, how will people recognise you at conferences/meetups? It could also be seen as dishonest. Luckily I still look quite like my avatar, though I don't wear those cherry bakewell glasses all the time.
Edit - a slightly amusing story - the first time someone came up to me and said "you're the guy with the funny eyes aren't you?"
"What?!" I thought, looking perplexed and mildly offended. This was a guy who'd written some of my favourite songs.
"The funny glasses?" he said.
Then I realised what he was talking about.
Edited by TheAlex, 08 January 2014 - 08:01 AM.