When in trouble or in doubt, invent new words. We have bibliometrics and scientometrics from the Age of Print. Now they are joined by informetrics, cybermetrics, webometrics and altmetrics, which might not be an accurate term, but it’s sticky (more than social media-based complimentary metrics, that’s for sure).
One of the challenges we face when using alternative metrics is the interpretation of what we measure. This is even more confusing than interpreting traditional citation impact (which is challenging and confusing in itself) because "altmetrics" is an umbrella term for a wide range of activities.