Is 是 being used as a measure word in this sentence? The sentence is:


  现在，中国网民总数已经超过美国人口总数，但美国网购人数占其全部人口的75%，中国则只有25%左右，而且，中国网购消费者年均消费额仅为美国消费者的1/5。于刚认为，这是差距， 更是中国电子商务的潜力。


Is '是‘ in 这是差距 working as a 量词？Or should I read 'this is a disparity'?
Not a measure word. Just the usual meaning of "be".