I hazard to propose that twitter contains closer to 99.999% crap. 90% might be the central point, but I think there is still variance between different mediums.

I hazard to propose that twitter contains closer to 99.999% crap. 90% might be the central point, but I think there is still variance between different mediums. Comparing nominal values without knowing the distribution can be dangerous, but that's why we have units of deviation, such as zscore.