I just want to share my method on getting active Google+ followers, most of whom are active (not fake accounts). They are not always targeted but this is a good starting point for those who want to show that their Google+ account got followers.
Fully fill in your profile and 1 post per day at least for 2-3 days (better to do it for about a week). That will show future followers that you are a real person
Find somebody who shares circles. Some people with many followers create circles that they share on their wall. If you can't find any of those a good starting point is this guy on Fiverr - fiverr.com/bosmol
Add people from shared circles. I usually create a new circle for those and call it "New Followers"
Wait for about a week. People will see that you added them, and some of them will add you back. While waiting, keep posting on your wall at least 1-2 times per week to keep your profile active.
If people didn't add you after a week, it's unlikely that they will, so it's time to clean up. Go to your circles and delete a new circle that you created.
Go back to your profile and see people who follow you. Those people who added you will be displayed there, add them back (since you deleted "new followers" circle, some people won't be added to any of your circles). I usually add them to my default "followers" or "friends" circle.
Then you just rinse and repeat. Keep adding people in circles, waiting for a week, deleting circles, adding back those people who added you.
As you add more and more people, see others who share their circles - when I find them, I usually put those people in a special circle that I call "Shareres".
Hope that helps!