Is a feature that is very needed. It IS already possible to create lists/workflows with a count of associated deals/tickets etc. So it would be not that much different from that.
The situation we have is that Contacts book artists, and will do this multiple times. Every time they will fill in their Company name, which will create a new company when they spell it differently every time. For example the first time they use Brandgang, but the second time Brandgang B.V.
We need a way to have insights in how many Contacts have more than 1 Company associated so we can merge the duplicates.