About that ‘portion’ of sales Apple pledged to fight AIDS

Apple has been saying for more than a week that it would donate “a portion” of the proceeds of every sale on World AIDS Day to the Global Fund to fight AIDS.

From the company’s Nov. 23 press release:

“For the next two weeks, a special section of the App Store℠ called Apps for (RED) will offer 25 apps with exclusive new content where all proceeds will go directly to the Global Fund to fight AIDS. In addition, Apple will donate a portion of sales at Apple’s retail and online stores around the world on two of the biggest shopping days of the year: Friday, November 28 and Monday, December 1.” (emphasis mine)

Today is World AIDS Day. Apple Stores around the world have turned their logos red and Apple’s online store is promoting its (RED) products:

  • New content for two dozen fan favorite apps, from Angry Birds to Monument Valley (100% to the Global Fund through Dec. 7)
  • A half dozen (RED) Apple-brand accessories, from $200 Beats headphones to a $49 iPod shuffle (a portion to the Global Fund)
  • Every iPad, Mac, iPhone, Apple TV sold by Apple (for today only, a portion to the Global Fund)

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Today is World AIDS Day, and the company still hasn’t said what that portion will be.

I’ve been puzzling about it. I can think of three reasons for holding back.

  • The portion is too small to mention — which seems unlikely given Tim Cook’s involvement in the fund-raising campaign
  • The portion can’t yet be calculated — or even estimated — given the uncertainty of future sales
  • Apple expects the dollar amount will be large enough — and the portion sufficiently generous — to save for another press release

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The publicity Apple gets for its charity work may be free, but there’s no reason to give it away.

Follow Philip Elmer-DeWitt on Twitter at @philiped. Read his Apple (AAPL) coverage at fortune.com/ped or subscribe via his RSS feed.

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