wbamberg/browserid-field-guide — comment on commit 65b7cab3d465d2f8a4761c43f0f98411f25dac4d
File: how_browserid_works.html line 69
By ozten:

Just to clarify:
You log into an identity provider once in a great while. There are two types of Identity Providers (IdP):
* Primary Identity Providers (who are mostly email service providers - hotmail, gmail, washington.edu, etc)
* Secondary Identity Providers (BrowserID.org)

Only Secondary IdPs need to do the email auth piece AFAIK.

Tough to saw which is the easiest intro narrative, primary only, secondary only or both.