Radiohead’s pay-what-you-want model turned traditional this week, and it appears the British band’s latest album, “In Rainbows,” could be headed to the top of the sales chart next week.

The album, which has been available for downloading from the band’s Web site since Oct. 10, was released on CD on Tuesday to conventional retailers The list price is now a less-flexible $13.98, although it could be found selling for as little as $7.99 at outlets such as Best Buy and Amazon.com. Early reports suggest that “In Rainbows” is on target to sell about 100,000 copies. Its biggest competitor is likely to be Mary J. Blige’s “Growing Pains,” which took over the No. 1 slot this week with sales of 204,000 copies in its second week in stores.

Despite “In Rainbows” being available for free for three months, this week’s CD release got a heavy marketing blitz, including a New Year’s Eve webcast on Current TV.

“We didn’t want to go out and jam it down people’s throats,” said Phil Costello, who runs TBD, through ATO Records, which has released the “In Rainbows” CD, and was a vice president at Radiohead’s former label, Capitol. “I think we did a good job of exposing the fact that we were physically putting an album and CD in the marketplace that was reflective of what people were able to download since Oct. 10. The real question is, who is going to show up and when, and how interested they in the fact of physical purchase? That’s the million-dollar question.”

At Amoeba Records in Hollywood, general manager Karen Pearson said the store has sold more than 400 “In Rainbows” CDs in its first two days and more than 100 copies of the vinyl edition. “Radiohead is, of course, a band with a solid base,” Pearson said. “The LP is selling actually better than anticipated.”

With overall album sales down around 15 percent in 2007 compared with 2006, according to Nielsen SoundScan, artists and labels are eager to experiment with new models, and the “In Rainbows” trial is now officially in phase two.

In the first phase, fans would determine how much they would pay, or whether to pay at all, for the online-only release of “In Rainbows.” “Really – it’s up to you,” fans downloading the album at www.radiohead.com were advised. The band and its management have remained tight-lipped on exactly how many downloaded the album. One Web site that surveyed Radiohead fans said that about 60 percent reported paying nothing.

In a year that saw Prince distributing an album free with a British newspaper, Paul McCartney aligning with Starbucks and Madonna signing with a concert promoter over a record label, Radiohead’s decision to make its latest album available for free was one of 2007’s hottest pop-music topics.

“If we would have put three more songs on it, then clearly your first-, second- and third-week sales would be much bigger,” Costello said. “… But is that the right approach to the core fan base? I don’t think so. And I don’t think it’s the right play for even the secondary people you’d pull in. I wouldn’t feel good about that move.”

A retail executive with access to first-day sales figures for “In Rainbows” says the album sold 40,000 copies New Year’s Day. If it does go on to sell 100,000 copies, that’s a significant drop from the band’s last album, 2003’s “Hail to the Thief,” which moved 300,000 copies in its first week. But few of the biggest-selling acts of 2007 have been able to matching their peak sales of previous years.

Radiohead traditionally has played for the long haul. “Hail To the Thief,” for instance, has sold around 1 million copies since its release. Another Radiohead spokesperson emphasizes that looking at the first-week tallies for “In Rainbows” and “Hail to the Thief” is “comparing apples to oranges,” stressing other factors beyond the Web availability, such as the year-to-year decline in CD sales since 2003, and the slow January market. Last January, for instance, the “Dreamgirls” soundtrack reached No. 1 with sales of just 66,000 copies, the lowest figure for a No. 1 album since SoundScan started tracking retail sales in 1991.

Yet Billboard Magazine’s director of charts, Geoff Mayfield, said there probably is only one reason to explain a large drop in Radiohead’s first-week sales compared with that of “Hail to the Thief.”

“It’s true you don’t have the sales volume in January that you have in December,” he said. “That’s obvious, but if you have a key release, the numbers will happen.

“It will be a decent number, and it’s an interesting number,” he continued. “But you can’t argue either a down market or a soft month to explain why the number is smaller than the last album. The elephant in the room is that you already made the album widely available months before it hit stores.”