You can set up goals in Google Analytics to measure how well your site accomplishes your target objectives. Sounds confusing, right? It's actually very simple. Say that your goal is to have visitors click on your product page to see what you offer (and of course, buy your product!) Then the goal you would define in your analytics dashboard would be something along the lines of X # of visitors visit product pages.
Useful goals to measure are ones that are part of your sales funnel and lead to ROI. Valueless goals would be along the lines of # of visitors that visit every page. You want to track the pages that make sense to your business goals. If you goal is to grow your eNewsletter list to increase repeat business, track it! If your goal is completing a purchase, track it!
Funnel Analysis goes hand in hand with goal completion. By analyzing the flow of how visitors get to each page you will be armed with valuable information on how you can change your design to better influence visitors to meet your goals.
Funnel analysis tracks the path in which a visitor takes to get to each page. Do they go from your homepage directly to products, or do they want to know about your company first? Does it take them three or four clicks to get to the most important information? You can use this information to develop better call to actions for your homepage and point visitors in the right direction.
If a strategy meets a goal: It's working. If a strategy meets a target: It's a success.