Lil' Kim (search) isn't free, and neither is her album, but fans were snapping it up so fast on Tuesday, it seems her prison sentence is helping her career.

"The Naked Truth" (search) hit store shelves Tuesday — several days after the singer began serving her 366-day sentence for perjury — and her adoring public said Kim's publicity blitz before prison and the timing of the album's release couldn't have gone better for the jailed songbird.

"I think she did very well [taking advantage of the timing]," said Brooklyn's Elise Elliott, 20, at the Times Square Virgin Megastore, where sales were brisk. "She covered a lot of bases — MTV, award shows."

Lucious Simpson, 18, of The Bronx, bought two CDs Tuesday in a show of support for the imprisoned rap princess — and will purchase even more discs when a paycheck arrives later this week.

"I think [prison is] going to make her stronger when she comes out," said Simpson. "Her next album is going to be even stronger. She needs this. She needs time for herself."

"The Naked Truth" may be hard to top, however.

The album has already received a "5-mic" rating from The Source magazine — the first time a female artist has received the highest, and rarest, accolade from the prominent hip-hop publication.

While many fans and industry wags think the album's release date was a little too coincidental, a source close to Kim insisted the work was going to find its way onto shelves in September regardless of whether Kim was convicted of perjury and sent to a Philadelphia federal lock-up.

The album's scheduled Sept. 13 release was only pushed back because of "a production screw-up," the source added.

But the sales are certainly getting a jump.

"When a female artist and style icon of her stature goes to jail, there's a natural outpouring of sympathy and interest in and of itself," said advertising firm Kirshenbaum Bond + Partners chief Richard Kirshenbaum.

But many fans said, jail or not, publicity or not, the album would have been a winner.

"She's never had a corny album," said Quincy Anderson, 26, a musician from Middlesex County. "It's going to go platinum anyway."