I'm working on a set of products and services under the same root brand name, that will consume five domain names roughly like this(hopefully much prettier
Parent brand book
Parent brand services group all services
Parent brand services group Service one
Parent brand services group Service two
Parent brand services group Service three
All of these sites will be developed in different time frames and different intensities of attention
The books site will be a standalone brochure site which may or may not have links to the others.
The all services site will be a kind of catchall of ideas.
The services two site will get a lot of direct attention and effort.
The services one and three sites will be just development sites for a while, maybe forever.
Since these sites will be developed in different timings, and I can copy theme formats between sites, I'm thinking that I'm going to just make them multiple sites with links between them as needed.
The apple pie in the sky is that the three details Service sites take on lives of their own and it won't be that useful to have them be entangled.
What I was hoping for with this question was for E experts to provide some ideas about why I might or might not want to use multisite.
Any input on this would be appreciated.