Managing multiple WordPress installations can be a drag. Remembering different sets of usernames and passwords, and having to install plugins and themes over and over again. Ain’t nobody got time for that.
Setting up a fresh WordPress Multisite installation and creating new sub-sites isn’t all that hard, but what about migrating an existing collection of sites into a new or existing Multisite installation?
There are many reasons why you might want to do this, for example you can:
Save time. Instead of installing and upgrading WordPress, themes and plugins across many sites, you can do all of these things just once.