Doug Clyde said
When I advertise I avoid those countries as well. I usually pick U.S., Canada, U..K. & Australia. I'm not sure how people from India and Singapore are finding me. Probably through Twitter, You Tube, or Radio Airplay. I'm glad to know those numbers are normal, and I'll keep that in mind when updating my follow-up e-mails. Thanks a bunch!

It's interesting... I have seen that happen as well but only when I run broad campaigns using the #interest (as apposed to precise interest). When I change my targeting to precise interest the foreign subscribers stop coming in. Either FB is a bit dubious with their targeting, in an attempt to make more money from you, OR many people in those countries are using US proxies and when you go broad you pick up a lot of those people because of the looser targeting. Were you using the broader targeting by chance?

Cool. Just make sure you didn't select the broad interests with the # symbol in front of the keyword. It's in the video but I see a lot of people over look it.

My best guess is that it's the foreign targeting. There may literally be a language issue (despite language settings) where people are having a hard time even understanding the instructions. 

Also, as a general rule I don't advise creating ads with too many different terms in the interest list. I try to just create one ad for one interest. The only exception is when they are very similar terms or interests (IE, alt country music, alt country musicians), or when the reach is so small that it doesn't make sense to create an ad just for 400 people, or whatever. 

You might try creating a new ad, with singular targeting, and then check your stats just for that new segment of your list. See if it's any different.

Or if you like you could just create a new list and turn off the double opt in requirement. I would separate your double opt in list from your single opt in list.