I received this today from Google.
“Today we’ve launched a change to our ranking algorithm that will make it much easier for users to find a large number of results from a single site. For queries that indicate a strong user interest in a particular domain, like [exhibitions at amnh], we’ll now show more results from the relevant site:
Prior to today’s change, only two results from www.amnh.org would have appeared for this query. Now, we determine that the user is likely interested in the Museum of Natural History’s website, so seven results from the amnh.org domain appear. Since the user is looking for exhibitions at the museum, it’s far more likely that they’ll find what they’re looking for, faster. The last few results for this query are from other sites, preserving some diversity in the results.
We’re always reassessing our ranking and user interface, making hundreds of changes each year. We expect today’s improvement will help users find deeper results from a single site, while still providing diversity on the results page.
Written by Samarth Keshava, Software Engineer”
I am not sure why they said this today. Google has been showing multiple results from the same site for about 2 years! Maybe they have only just realised. Lol.