The "BET Awards" turned into an impromptu Michael Jackson tribute, and preliminary ratings show that it will have the event's biggest audience ever.

Nielsen Media Research says the ratings from its 56 biggest markets showed Sunday's "BET Awards" were up 61 percent compared with last year. An estimated 10 percent of turned-on television sets were tuned to the "BET Awards" -- an unusually large number for a cable channel, the Associated Press reports.

Nielsen says the show got a 5.8 rating in the overnight ratings. The awards ceremony has been held since 2001 and has never gotten more than a 3.7 rating.

Several celebrities, including host Jamie Foxx, paid tribute to Jackson.

The evening was capped by the emotional appearance of Jackson's sister Janet.

But many who watched the awards show were disappointed, with viewers posting complaints to online entertainment and social networking message boards.

"That was no tribute. That was a travesty," said one person about the show at EW.com. "That did not honor Michael in anyway what he deserved. And as far as Foxx goes, have been a fan of his but not so much now. Shameful performance all around."

Wrote another viewer on EW.com: "I'll be honest, I was disappointed. The only reason I watched was because I was told they were honoring MJ. No one really said anything. Like someone said they should have waited and done a REAL tribute. ...

Meanwhile, promoters say fans who bought tickets to Michael Jackson's 50 canceled concerts in London will receive a full refund.

Los Angeles-based tour operator AEG Live said in a statement today in London that all those who bought tickets through an authorized agent will be refunded the cost of their ticket and service charges.

AEG Live says details will be provided at the Web site www.MichaelJacksonLive.com tomorrow. It says fans can choose to take a refund, or instead receive their actual ticket, which the company said features graphics designed by Jackson.

The offer to receive the ticket will continue until Aug. 14, AEG said. About 750,000 fans bought tickets for the shows in London, which were due to begin July 13 and continue until next year.