For those who have searched over and over online for ways to invite all friends to your Facebook events I have found the latest method that works, but it requires Google Chrome.
Here is a video on how to create Facebook Events and select all your friends to invite them to attend:
Until I found one extension that did, this was the Facebook Add All Friends Google Chrome extension and it works perfectly and was able to allow me to select and invite over 2,100 friends to my Video Game Giveaway.
To use this plugin just create your Facebook Event (don’t invite anybody yet).
After your event is created, click on your event and click “Invite Friends”
Then click use your mouse and scroll down your friends list until you reach the end (z’s) and you see all of your Friends listed.
Click on the Select All Friends button and wait a bit, this can take over 2 minutes if you have thousands of friends.
You will see them all get selected, then click the “send” button.
Note: Facebook will likely present you with Captcha to confirm the send and make sure you aren’t a spammer.
Friend Invite Etiquette
Now, the first thing I would tell you is not to abuse your friend network and send out mass invites for no real reason. If you are hosting a local event, you have no reason to invite people living in other states our countries for the most part. If you are launching a new product, service or giveaway online these would be valid reasons to to a mass event invite but use it sparingly, I would do no more than 1 event every month or less frequently or else you are spamming your friend network.
Still, the ability to send event notifications to fans directly is a powerful edge to Facebook profiles that Facebook Fanpages lack, they can’t directly contact fans who like their pages to notify them of anything, just post to their wall and hope that your fan notices or follows closely enough to see it.
Also with Facebook having “subscribers” for profiles instead of just friends you have no way to invite subscribers, so I do think that Facebook invitations will get eventually less and less useful as there are other non-friend added ways to interact with your fans/audience.
For now though, few things are more powerful for getting attention to a launch or massive contest as sending out an event invite and I recommend you do it either at the launch of a contest or a few days before it ends, this way enough people can have time to check out the event assuming it can take 48 hours for people to check Facebook.