Thousands of people were left disappointed after trying desperately to buy Olympic tickets and missing out - so the sight yesterday of row upon row of empty seats at several venues will have left a bitter taste.
One sports fan labelled the situation "a disgrace".
It also meant the atmosphere at some events wasn't quite as electric as it could have been.
As a result organisers have launched an urgent investigation into the matter.
The gymnastics arena was one of many venues containing rows of empty seats
Gaps were visible at a number of venues, including the Aquatics Centre where British medal hope Hannah Miley missed out on a podium place, at the North Greenwich Arena.
In contrast, huge crowds lined the streets, where tickets were not required, to watch Mark Cavendish and Team GB compete in the cycling road race.
Culture secretary Jeremy Hunt said the empty seats were "very disappointing" and suggested they could be offered to members of the public.
He added: "I was at the Beijing Games, in 2008, and one of the lessons that we took away from that, is that full stadia create the best atmosphere, it's best for the athletes, it's more fun for the spectators, it's been an absolute priority.
"Locog are doing a full investigation into what happened, I think it was accredited seats that belonged to sponsors, but if they're not going to turn up, we want those tickets to be available for members of the public, because that creates the best atmosphere.
"We are looking at this very urgently at the moment."
He said a system had been introduced for these Olympics similar to the one used at Wimbledon, where people coming out of the stadium handed on their tickets so the seats could be made available to other people.
"So we are trying a lot of innovations, it's a shame this happened, but we are going to do everything we can to make sure we fill up these stadia."
Gaps in the seating were also visible at the gymnastics, handball, volleyball, badminton and basketball arenas yesterday.
The cheaper seats higher in the stands were mostly full but those lower down, which are generally more expensive, were not filled.
Huffington Post UK reader Nathan Walton said on Facebook: "It's a disgrace."
One basketball spectator, Jane Smith, from London, said: "It's very disappointing to see this, particularly as we all tried so hard to get our tickets. It doesn't help the atmosphere at all."
Other fans took to Twitter to express their concerns.
One fan wrote: "All those empty seats should have been given to the locals or sold on first come first serve on the day. Games are looking real empty!"
Another Huffington Post reader reported that he'd tried to buy tickets for the gymnastics today, but the only seats available cost £150. "Prices are too high at a time of economic pressure," he said.
A spokesman for Locog said the majority of the empty seats were believed to belong to accredited groups such as governing bodies and the media.
He added that some tickets remained unsold and urged members of the public to check online for opportunities to attend the games.
Olympics supremo Lord Coe called for the row over empty venues to be kept in perspective.
Asked if sponsors who failed to turn up would be named, Lord Coe said: "I'm not sure naming and shaming is what we're in to at the moment. I don't think you will be seeing this as an issue long-term into the Games."
Lord Coe said more tickets could be sold, while others could be offered to troops.
But he stressed it was still early on in the competition.
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