So Paul Chambers, who has the patience of a saint by the way, wrote this "Explanation for Dummies" for me. I think I get it now, kind of. Having said that I tried his example and the Auth bombs out for some reason?

I see an issue. dickturpin@identi.ca anddick_turpin@microca.st are two different accounts. 

create a new account at microca.st and choose another server instead of new login name and account. The other server info will be theidenti.ca account.

Then you can follow me at p37307@microca.stfrom your main identi.ca account. You should only have a login logout opportunity over atmicroca.st.

One place to post from among different services. If you choose identi.ca as your main account, keeping your established relationships over there then that is where you will post too and anyone over at the other pumps, that are linked withidenti.ca will be able to follow you from there. Make sense?

In other words, let use the big three and assume they use pump.io.

Say Facebook, god forgive, is your main social media account. You make friends there, make posts, etc. Now you can Log in to Google plus with your Facebook credentials. From there you can only log out of Google Plus.

But you can now go back to Facebook and create posts, upload pics, whatever. Your Facebook people will see. Now you can circle people from Google Plus. Google plus people will now be able to interact with you on Facebook and they will see your posts.

Now throw in twitter. Go to twitter and join up using "an account on another server."

Now whatever you post on Facebook will go to twitter and Google Plus. You will be able to make friends with people from G+, Twitter and now Facebook.