I was wondering if anyone could shed any light on the trend I've seen in relation to one of my sites on Google over the last 4 or so days.
According to Webmaster tools, over a period of 4 days:
the number of my pages in the index has more than doubled.
At the same time the number impressions being served (and as a result, clicks) has halved.
I doubt this is a coincidence, as until now the number of pages in the index was fairly static, and the impressions were on a fairly predictable slope.
However, I'm puzzled and intrigued as to why these two things are connected in this way. One might expect the number of impressions to increase with the number of pages in the index. But how can the inverse relationship be explained?