I have multiple personal websites that I develop and plan to develop more over time. The number of websites is currently greater than one but less than 50.
Currently I have a single Google account with a single analytics account that has a web property for each of my sites. My understanding is that you can have up to 25 analytics accounts attached to a single google account and each of those 25 acccounts can have up to 50 web properties in them which would allow me to track up to 1,250 sites.
I don't think I'll be hitting that number anytime soon, however are there other reasons to structure accounts differently, such as using a separate google account for each site and then adding myself as an administrator?