Quoting myself is fun:

That is the limit of the average gamer's capabilities.

*takes all the fun and runs away*

Asking why people would want to track sales of games is about as silly as asking why people would want to play games. It all comes down to boredom, stress relief, and just a general desire to do something besides the usual daily grind. There are some who find tracking sales data to be as enjoyable as playing games (odd though I'm sure that sounds). We can come up with all the reasoning we want for it, but unless you're actively a part of a firm which focuses on this sort of thing, you're basically doing it as a hobby. Meaning it all boils down to distraction.

That doesn't really address my comment, it just repeats what you said before.

Do you think people should ignore the news because they, by themselves, cannot directly effect or shape the policies of the world?

I didn't address your comment because you made a very flawed analogy.

A better one would be:  Do you regularly go online and discuss/follow the viewer ratings of your favorite news or TV program?

Essentially we have a hobby and a tangential hobby that is related to the former.  Your analogy lacks the tangential aspect.

Sales are important to gamers because it makes them happy or unhappy when lots of people bought the games they like and vice versa. It´s also important to them that their favorite games sell enough in order to be sure that such other games with better quality keep coming.

However, thinking too much about sales can lead to the outrage of the inner fanboyism of a gamer and pointless war-sales threads show up. Also, fanboys that are on the "winning" side may use sale numbers in order to show that their games/consoles/handhelds of choice are better because they are more popular.

Sales numbers should be used by gamers in order to have a better picture of the global gaming industry economy and analyze how a certain company or genre is doing. Nothing more than that and certainly sale numbers shouldn´t be used for judging the quality of games and companies.

Because it gives gamers boasting rights about their own consoles that they made the right choice in selecting the "winner". It's just the mentality, no one wants to pick a "loser".

The analogy is perfectly legitimate, it almost seems as if you thought some big words would confuse me, sorry to dissapoint if that was the case.

Contrary to what you seem to believe, the subject matter of the "source" in an analogy is not required to be tangential or even related in any way to the "target" subject matter. 

The very point of the analogy is to move away from the subject, to something you can relate to more readily.  For this added ease of comprehension/illustration you don't always get the perfect analogy.

In any case, you're really only dodging the question, would you like to answer? Of course avoiding the question is itself an answer but I figured I would offer anyways.

I'm avoiding a meaningless question because you can't make the analogy that news is akin to video game sales data alone.

News would be more akin to video game sales data and console updates and release lists and much more.

Some of it is highly relevant: Recent crime in your area akin to the console update coming out tomorrow.

Some is somewhat relevant: A new bill coming to legislation akin to release lists for games coming later on.

Some is mostly irrelevant: The scores for all the local sports games akin to video game sales data.

There are people who are totally into local sports but a majority usually aren't unless they're directly involved (children, friends, participation). Likewise, most gamers don't care about sales data unless they're directly involved (chatting on a sales forum).

And no, I'm not trying to confuse you with "big words" but if they do confuse you I can use smaller ones. ^_^

when you buy something you want to feel like you made the right decision so if it is doing well you are happy.
if it is doing bad you bought a dud.
that is why i am happy.