As we mentioned before, when someone finds your site via a link on a social network, they'll be bucketed under social media as a traffic source. This could include someone tweeting out a link, or it could include you posting a link to your Facebook page. If it's you doing the posting, you can also add a tracking token before posting to track those links as part of a larger campaign for you to analyze later!
This is the number of views that you can test each month on your website.It's up to you how you choose to use them, either by allocating all the views to one test or to multiple test, either on one page or on multiple pages. If you have selected the 10.000 tested views plan and you run an experiment on your category page which is viewed 7000 times per month, then at the end of the month 7000 is what you'll be counted as tested views quota.