The next best thing to sitting beside someone browsing your site. See where they click, ask what they think, and learn why they drop off. Get started for free.
You should encrypt all the outgoing URL in posts. Before redirecting to original website, just save the click data in database. This way you will be able to keep track of it.
Though to prevent info about data being clicked by bots and all, you should add some filters/checks. This way you will be able to keep track of every click, even if some antivirus is blocking click tracking service.