While this isn't strictly a Joomla tip, it's certainly something that has helped me more easily track the volume of traffic that comes from specific posts I make on forums and social media sites.
One of the reasons I find this necessary is that I'm very active on multiple forums and often reference my own blog posts when helping others. While it's easy enough to see that a certain amount of traffic is coming from one of these forums, it can be a little tougher to get an idea of which specific discussions are generating interest.
So I use a very simple trick and append my URLs with an identifier. For example, in a recent post on the K2 community forums, in a discussion about tagging, I used my own blog as an example. The URL I gave them was http://thinksync.com.au/blog?utm_source=SBF&utm_medium=forum&utm_campaign=tagging.
I generated this URL by using the Google URL Builder.
Now in Google Analytics, I can look in my campaign view and see 'tagging' appended to any traffic that arrives at my site from that post.
This is great intelligence, helping me to determine which topics are popular and worth spending time on for future posts.