It amazes me that Twitter exists. My marketing guy convinced me to start tweeting for business. The ROI we hope for is completely based on serendipity. Dropping leaflets from a plane might have a better result...
(Hmmm, business idea: p-tweets - physical-tweets. Messages printed on ping pong balls and dropped from 30,000 feet)
Adam Savage replied to one of tweets a few months ago. That was my 1 minute of Twitter fame.
Based on the numbers in the article I'm in the top 10%. Yay me. Actually, that is kind of sad. I post to Twitter most days, maybe 1 to 3 things a day on average, 90% of which are ignored without a reply or retweet. If that represents the top it doesn't really speak well of Twitter.
I mostly keep my twitter account as some sort of a diary where i post cool stuff i occassionally come across that basically means i dont care about followers but anybody is free to follow me.