I have no social media presence myself, but I'm thinking it would be good to:
Contact all Amiga podcasts to let them know. Send them a freebie for review.
Join Amiga groups on Facebook, Google+ amd whatever else is used these days.
Ask all retro commercial sites for support by offering them the option to supply it, maybe receiving a cut of some cents?
Publish on Amazon for Kindle fire. I'm told by an author its not hard to self publish. Same for Android. Apple Newsstand?
Kickstarter to fund future issues in advance? (Do the others first thoughfor the awareness)
Create Twitter etc accounts so people have a way of spreading the word easily.
Create a presence on all the Amiga forums. Not just this one.
I'm happy to take ownership of some of these. But I wouldnt forward a copy of the pdf to anyone. I think tge ones sent for review should be specially branded to prevent redistribution.
I've read some free ones. Theyre not the same. Also, its good to support enterprise here. A community of people unwilling to pay even a little for quality is not healthy IMHO.