I know this has been discussed before in various contexts, but I'd like to see if anyone will volunteer a current opinion on subdomains vs. subdirectories in a multisite installation. It will be a network of separate blogs (users setting up their own sites).
Subdirectories are a little more beneficial to us for a couple of technical reasons. However, if there are any real advantages to subdomains, and if users generally prefer it, we'll need to evaluate our strategy.
I have heard that subdirectories have two advantages from an SEO standpoint:
1) I heard that Google sometimes limits the number of subdomain results in a search due to an epidemic of subdomain spam, so subdirectories might sidestep this limit.
2) I have heard that subdirectories can get indexed faster because they are under the main site domain that's already been indexed.
There is also another advantage to subdirectories: We don't need a wildcard SSL certificate to allow users to login to their Dashboards securely...since all sites will be under tha main domain.
So there are quite a few advantages to subdirectories from our point of view. But again, we want to hear opposing viewpoints and get a good idea as to what people want.