A FUP often applies when using an Internet connection. You may download it, but it should not be done constantly so that other users are bothered by it: it is therefore not allowed to be extremely much data user. What happens when the FUP is violated varies by contract, it may be that no data traffic is possible at all, or that an additional account is coming. Because Fair Use is rather opaque, you don't know as a user when you are violating it.
By creating a deeplink, a user is immediately directed to the right content (instead of To a meaningless home page). Search engines use deep links to determine the quality of a website (quality score), if there are many deep links, then it is an interesting site than the reasoning. A deeplink to this page is: http://www.wat-betekent.nl/wat-is-deeplinking/. In the past, there have been lawsuits to deep linking, because news sites In particular were not happy with the fact that people directly linked to an article (which caused them to miss a lot of ad revenues on the home page). Therefore, it is not allowed in all countries either.