Here's one explanation for the empty seats at the World Cup

For complete World Cup 2014 coverage, visit Yahoo Sports and follow @YahooSoccer.

RIO DE JANEIRO — There have been a lot of complaints during this World Cup, but the one that seems to be ringing from nearly every person in Brazil is the outrage over ticket prices, especially for games involving teams in the Americas.

So, let’s add a little gasoline to that fire, shall we?

[Slideshow: Ranking the most expensive World Cup tickets by country]

According to SeatGeek, several tickets to matches were returned either by teams or sponsors and those tickets were not reallocated by FIFA. So, provided that is true, there are tickets just sitting in the electronic ticketing ether that are going unused. Those tickets could have been resold to fans at face value or handed out to underprivileged communities in Brazil so they could have experienced the joy of the World Cup. With all the ire Brazilians have about this World Cup, a little goodwill would have gone a long way.

But no, thanks to some sort of clerical error, tickets will go unused. Of course, FIFA plans to investigate.

Thanks to the failed ticket distribution, the secondary market for tickets has been booming.

[Related: U.S. chokes away chance to advance]

According to SeatGeek, of the 14 most expensive average ticket prices, 13 have included games with teams from the Americas. The only exception was the game between Belgium and Russia, which was going for an average of $801 on the secondary market.

Tickets for the World Cup opener between Brazil and Croatia averaged $2,667 and the game between Brazil and Mexico was $1,739. Tickets for USA’s game against Germany are already averaging more than $700 and are expected to go up.

For the average ticket buyer, prices are much higher for games in major cities as opposed to those in some of the more remote venues. Tickets for Sunday’s game between the U.S. and Portugal went for a paltry $174, but patrons also had to find a way to get in and get out of the Amazon rainforest city of Manaus.

The high ticket prices are what drove 85 ticketless Chilean fans to rush the media center at Maracana Stadium in Rio in an attempt to watch their national team play Spain. All 85 of those patrons were asked to leave the country; 57 have already left while the others are subject to deportation if caught.

Some German fans actually gave underprivileged Brazilian kids in Salvador tickets to the Switzerland-France game because they felt bad that Brazilian people were getting priced out of the tournament.

And tickets won’t get any cheaper as the World Cup continues to inch toward its finale. But who knows? Perhaps FIFA has a stash of Round of 16 tickets just sitting on someone’s desk collecting dust.

Related World Cup coverage on Yahoo Sports:

Graham Watson is the editor of Dr. Saturday on Yahoo Sports. Have a tip? Email her at dr.saturday@ymail.com or follow her on Twitter Follow @Yahoo_Graham