Chris Brown earns his second No. 1 album on the Billboard 200, as "Fortune" debuts atop the chart, selling 135,000 copies, according to Nielsen SoundScan. It follows his last release, and first No. 1, 2011's "F.A.M.E." That album launched atop the list with 270,000 - more than double that of "Fortune."

Brown is the second R&B hitmaker in a month to debut at No. 1 with a comparably soft launch (see story, page 9). Four weeks ago, Usher's "Looking 4 Myself" started at No. 1 with 128,000. That marked a significant slide from the first-week sales (329,000) of his last full-length album, the No. 1-debuting "Raymond v Raymond."

Had it not been for Brown's "Fortune," there would have been a surprise return to No. 1 for Katy Perry, as her "Teenage Dream" set zooms from No. 21 to No. 2 with 80,000 (up 417%), notching its best sales frame since Christmas 2010. The set was one of 20 titles that Amazon MP3 sale-priced for 99 cents for one day only (July 3). (The Google Play service matched the pricing, but it wasn't highly promoted. It's likely they contributed a small total to the sales spike.) Perry also benefits from buzz earned from current single "Wide Awake" and the release of "Katy Perry: Part of Me," which hit U.S. theaters on July 5.

All but one of Amazon MP3's 99 cent sale titles rank among the top 40 on the Billboard 200, and 17 of them post a gain of more than 100%. The largest percentage gain goes to Ellie Goulding's "Lights," which vaults from No. 116 to No. 21 with 23,000 (up 444%). It's both a new weekly sales high for the set and its best rank yet.

Amazon MP3 also pushes three more albums back into the top 10 aside from "Teenage Dream" - Gotye's "Making Mirrors" (31-6 with 44,000; up 248%), fun.'s "Some Nights" (23-7 with 43,000; up 181%) and the Black Keys' "El Camino" (55-10 with 37,000; up 396%).

Just outside the top 10, Jason Mraz's "Love Is a Four Letter Word" rises 45-13 with 32,000 (up 255%), also thanks to Amazon MP3.

All of the Amazon MP3 action blocks Flo Rida from earning his third top 10 album, as his new "Wild Ones" debuts at No. 14 with 31,000. It's likely that without the Amazon MP3 deal, his album would have bowed at No. 9, as there are five discounted titles that jumped ahead of the rapper this week.

But at what cost? So, just how much did the 99 cent promotion cost Amazon? Sources tell Billboard that the labels worked with the retailer on the promotion, extending discounted wholesale costs. So determining how much of the cost Amazon ate is tricky. But, that cost may have been nearly $2 million.

So, how did we come up with that figure?

Combined, the 20 titles sold 454,000 downloads last week. While we don't know exactly how much of that figure is owed to Amazon MP3 (and Google), we can make an educated guess as to its volume.

The week previous, the 20 sold just 64,000 digitally. If we assume the bulk of those sales came from the iTunes store - as the digital market leader, by far - then let's guess that maybe 50,000 of the 64,000 were from iTunes. Again, we're just estimating.

Of the 20 titles, none were brand-new, so they shouldn't have experienced any major fluctuations in sales this week had it not been for the 99 cent promotion. (Only Katy Perry's "Teenage Dream" would have likely had a big boost, thanks to her film's release.)

That said, the 20 albums would have probably sold about the same number of downloads this week as last week - if Amazon MP3 hadn't promoted them. So, if we subtract the estimated 50,000 that iTunes may have sold this week, we're left with 404,000 that Amazon MP3 may have sold at 99 cents. (Again, Google was probably a small player in this week's increase, and we're choosing to remove it from the equation.)

Now that we have an actual figure to work with, we can try to work out just how much money may have been spent by Amazon on this promotion. At least, the funds lost in the cost of each album to Amazon, versus its 99 cent price to the consumer.

Billboard understands that the bulk of the titles in the offer had a discounted wholesale cost somewhere in the range of $4.50-$6.50. To simplify matters, let's assume that all 20 of the titles have a regular digital wholesale price of $5.50.

Based on that average cost of $5.50, if Amazon MP3 sold 404,000 at 99 cents each, that would mean the promotion could have cost the company $1,822,040. ($5.50 for 404,000 albums equates to $2,222,000, minus the $399,960 generated by the 99 cents sold for each title.)••••