Not Provided vs. Not Set in Google Analytics

What is the difference between Not Provided and Not Set under the keywords section in Google Analytics?

Answer:

Not Provided occurs when a user is browsing on an encrypted URL at Google.com. If you are logged in to your Google+ account, you will automatically be on https://. This means the more users that use Google+, the more you will not be able to see what keywords brought them to your website.

Not Set is simply a referral or direct visit with no keywords that are allowed to be passed. Sometimes a user can search from their browser and end up on the site and this may propagate (Not Set).

Tip:

You can click (not provided) and view the landing pages as a secondary dimension to at least figure out what pages are being viewed the most. You could also compare this to the known organic keyword traffic and attribute a estimated percentage in distribution to each known organic keyword.

Click to Enlarge - You could also do unique page views for increased accuracy to attribute to other relateed keywords for each individual content page.