In reply to ERIN.

Hey, I was there.

First of all, it was a special concert after the end of the Open'er Festival, organized by the same concert agency. And people who had 4-day tickets to Open'er could attend Rihanna's concert for free - so the fact is, many of the people waiting for her concert were NOT her "biggest fans in the world", some people just know a few of her songs because they hear them at parties etc. And they came to the concert because they didn't have to pay any more.

From 3rd to 6th July bands like Blur, Arctic Monkeys, Queens of the Stone Age and Kings of Leon were playing on the same stage as headliners.
On 7th July Dizzie Rascal was playing as Rihanna's support at 8 pm and ended his show at about 9:15 pm. The next 45 minutes were for the stage technicians and at 10 pm everything was ready for Rihanna.

Rihanna came out at 10:55 or 10:56 pm, after people were booing a few times and chanting "Beyoncé!". People in the crowd got really angry, because they were waiting for the show over 1,5h, when you include the break for the technicians. But come on, Bey paying them? :D That's just ridiculous...

During the first few songs I was under the impression that Rihanna was drunk. After she sang "Man Down", the show got a little better, but for me it was pretty much the worst show on that stage, although I really like many of Rihanna's songs.
I just feel sorry for the people who had paid a lot to see this concert (I was in the group with 4-day tickets to the Open'er Festival, so I didn't spend that much on this show).