Averages are the mind-killer. Don't show me the average, show me the distribution. Any time that you present an average over a data set that isn't approximately a normal distribution, you're committing statistical malpractice.
Put another way, don't give me a measure of center (mean) without a corresponding measure of spread (variance/standard deviation).
Providing a measure of center for something that is approximately normal doesn't obviate the need for a measure of spread--you could have two distributions with the same mean but wildly different spread of results due to variance.