Lindsay Lohan’s 23rd birthday isn’t until tomorrow, but she’s already managed to profit off the day.

According to sources, the troubled starlet was paid a cool $70,000 by the MGM Grand in Las Vegas to host an all-day “pre-celebration” at the hotel’s Wet Republic pool party last Saturday.

At the event, which served as a promotion for her Sevyn Nine self-tanning mist, Lohan changed bathing suits five times before throwing on club gear and dancing to Michael Jackson songs for the rest of the night.

But friends of Lohan say the event was less of a celebration and more of an urgent attempt to pull in some cash. “None of her really close friends were there,” said our insider, who noted that ex-girlfriend Samantha Ronson was also missing from the festivities. “The only person who was even known was Brittny Gastineau.”

Lohan didn’t drink at the party and actually allowed her photo to be taken. She was also overheard saying she was still distraught from publicity over the disappearance of jewelry she’d modeled for a recent Elle magazine photo shoot in London.

The hard-partying actress is planning to have “a small private party with friends in LA” tomorrow, according to our source — but her mom, Dina, and sister, Ali, have been asking her to come home to Long Island and spend her birthday with her family.

This wouldn’t be the first time Lohan has tried to make a buck off her birthday. She was scheduled to have her 21st bash in conjunction with Las Vegas nightclub Pure, but the party was canceled after Lohan checked into rehab. She also tried to find corporate sponsors for her 22nd birthday by setting up a Web site. A rep for MGM did not return a request for comment.

Source, Bauer-Griffin