over 50% of all the edits [to Wikipedia] are done by just .7% of the users—524 people. And in fact the most active 2%, which is 1400 people, have done 73.4% of all the edits.
Of course, this could all be a non-issue, but how may people contributed to the last edition of the Encyclopaedia Britannica? Was it more or less than 524? Or 1400? Is it essential to the value of Wikipedia to have a large number of active contributors? Or is it enough that potentially anyone could contribute to Wikipedia?