What data is Google Analytics Goals unable to track?

Goals measure how well your site or app fulfills your target objectives. A goal represents a completed activity, called a conversion, that contributes to the success of your business. Examples of goals include making a purchase (for an ecommerce site), completing a game level (for a mobile gaming app), or submitting a contact information form (for a marketing or lead generation site). However, you can’t set some kind of data as goals and track it. This includes Customer’s lifetime value for example. Tip: Goals are limited to 20 per reporting view. To track more than 20 goals, create an additional view for that property.