UPD: The script linked in the article doesn't work anymore, I recommend you to look for Google Chrome extensions like Invite Post Likers, there you can find working variants, but don't test on important accounts, check first on ordinary autoregs.
Want your fanpages to live longer and not fly off unpublished? Invite people who have interacted with your ads to like your page!

The more social interactions, the better for Facebook. And so you don't have to invite everyone individually by hand. here's a little script.
It should be made into a bookmarklet and installed on the browser's bookmark panel. Watch this video to see how to do it.
Next, go to the page of the ad post and click on the script. It will first scroll through and open all of the ad's likes. This will take some time if you have, say, several hundred likes. Then it will select all the "Invite" buttons and scroll through them all!
The browser may hang for a couple of seconds, and then - voila, all users are invited!
That's all, pour on the plus side, gentlemen!)