WMT source domain count dropped... is an update round the corner?

[AnkitMaheshwari]

Today morning I saw the source domain number dropped for most of the pages in Google Webmaster for one of our domains. The drop in number is as high as 60% for some important first level pages.

No PageRank or traffic changes noticed yet however, the impression count has also dropped by around 35-40% in last two days that WMT shows with no significant changes in keyword ranks.

Anyone else noticing the same changes?

[tedster]

If the impression count is down, that could mean some algo change has already occurred - either that or a WMT reporting change (either a fix or a new bug). I would strongly suspect the second.

[cloudtap]

It's just a reporting change, the same thing happened with one of my test sites but the actual rankings and such remained the same and our google analytics had a huge discrepancy versus the ranking and data from google WMT

[AnkitMaheshwari]

Correction: The impression count was actually down by 15-20% and NOT 35-40%

I tried finding which domains were actually dropped. However, no exact pattern found.