I send my CSAs a weekly newsletter, and I make sure they are included on all my stream posts, except for the ones intended for PSAs only.
The information I send is the same for everyone; I would prefer the sponsor do that instead of me, but since I don't know the level at which their sponsor interacts with them, I don't want to leave them out of anything.
And since I do receive commissions on their purchases, I feel they are just as important as my PSAs.