Sgt_Kickaxe - 3:14 am on Feb 10, 2012 (gmt 0)
Panda has wreaked havoc on duplicate content of all kinds.
It used to be that a group of words was duplicate only if they were in the same order. Now a group of words can be duplicate in any order and without even having all of the same words. You can see that when you search for exact match titles, swap words around and the same article is returned more often. This is especially true on heavily repeated titles such as those found in product feeds.
As for the subject of this thread I'd try to have only minimal identical text on each site and encourage owners to write their own unique copy. You'll also want to let them use a keyword or company name in the url since "site 1" or "1234567" says nothing about the subject and neither does the tld.