How many times should I post on Facebook?
A Facebook post will earn you 5 points, and you can usually earn up to 10 points for Facebook on a Mission (but sometimes it's more.) That doesn't mean you should post the same thing multiple times until you hit the max amount of points. Your friends wouldn't want to see that, and it's not helpful for a brand either.
Instead, spread out your posts through the length of your Mission. You can share first about the new Mission you accepted and then again after you've tried the product. Then, continue to update us, the brand and your friends as you have new pieces of feedback to share about the products you're trying.