Okay, fellow newbies! (I'm a PC newbie, been playing the game for a while online.)
Editing ONCE AGAIN as I figure more things out.
There are sections to this thing called Diggy's Adventure, most of whom can't talk to each other.
1. This forum here. All this is, is a message board, that lets you put out public messages, like these ones we've been using to try to get neighbors. Other threads will let you find and share tips, etc.
2. The portal (https://portal.pixelfederation.com), where you can play the game as well as request/accept friends, but the friends there are ONLY FOR PRIVATE MESSAGES. As I discovered by reading early posts in this thread, friends on the portal do NOT become your neighbors in the game. So, I've deleted my detailed instructions on how to do that because it's not what we're looking for.
3. Facebook game. THIS IS THE ONLY WAY TO GET NEIGHBORS. You friend somebody on FB, then open the game in FB to sync it. You don't have to play the game on FB if you prefer the portal, but you must open it in FB to add your neighbors.
4. Mobile app. You can play there, but you can't visit friends. You do still get the benefit of any windmills. Personally, I like the game play on my tablet better, so I'll log in daily on FB for new friends and gifts, and then switch.
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TL;DR:
The only way to get neighbors is to become Facebook friends, and then log in (at least once) via Facebook. Put a link to your FB account in your "add me" message. Mine is https://www.facebook.com/jenna.sayquah.5
Hope this helps us all get the game neighbors we are hoping for. 😃