Personas are collections of information about your personal strongest interests. They can include your job or business, the sports you watch and play, your hobbies, your avocations, your charities, and more. You can have as many as you like and they are fully in your control.
Why publish personas?
It's a great way to represent yourself as a serious multi-talented person.
It's a public calling card for each of the things you love to do and do seriously.
You can use them to stay up to date with the communities of interest you are serious about.
You can expand your network for the things you love without social network confusion.
They are great for personal branding and finding you in search engines.
ThreeSpaces is for personal self-promotion. Personas are public. You should post only public information on your persona profiles.