The averages are calculated based on the users of the app, so the average is actually the "Average of other people who use the app". The first time i ran this app, the average sat at around 400 while the min was around 30 and max well over 2k.
I actually have a basic URL i've setup which shows the performance stats of how the app is running, its an interesting watch.
You did pickup on a known bug, if the worker processes are very busy they can takes around 30 seconds to display your stats the first time. If you re-visit the app your stats should be there.
Sorry for that. Also please see the blog post we created yesterday, didnt think to post that here. That is a good suggestion. http://bitchasscode.com/?p=111
Ive certainly heard of people who would use it, but there would be a lot of concerns around privacy and security of information. I personally think gmail has most of the market here by providing automated translations, the big companies who want something better (and are willing to pay for it) probably use their existing translation partners....
Although...honestly...id you can solve the privacy issue and make an experience where someone sends an email and selects the new language, and the person receiving the email doesnt even see it until the translation is complete...it could seem very seemless and accurate, people might love it. I would, if i needed it.