After an initial rush, downloads of Microsoft's free Office for the iPhone quickly tailed off, data from a mobile app analytics company showed Sunday.
But at least 200,000 copies of the small suite -- iPhone versions of Word, Excel and PowerPoint -- were downloaded in the first six days.
Distimo, a Dutch firm that tracks app store market data for several platforms, including Apple's iOS, Google's Android, and Microsoft's Windows 8 and Windows Phone, said Office Mobile for the iPhone debuted in the No. 10 spot on June 15, the day after Microsoft launched the free app.
That was Office Mobile's peak: On June 16, Office Mobile slipped to the No. 19 position among all free iPhone apps, then continued to slide throughout the week of June 17-23, starting that seven-day stretch at No. 36, falling to No. 86 by Friday, June 21, and ending at No. 299 on June 23.
From June 24 to July 6, Office Mobile was not on Distimo's leaderboard, which lists only the top 400 downloaded apps.
The number of downloads of Office Mobile for iPhone is unknown -- Distimo requires a paid account to show developers the estimated downloads of their apps and those of competitors, and did not reply to questions Sunday -- but the tally was probably significant.
According to Distimo (download "What Is Needed For Top Positions In The App Stores?" as a PDF from here), to place in the App Store's No. 10 spot, an app must average 72,000 downloads daily. Office Mobile was ranked No. 10 on June 15. Apps ranked at No. 50 averaged 23,000 downloads daily: Office Mobile held position at No. 50 or lower for five consecutive days.
Those numbers implied that at least 200,000 copies of Office Mobile were downloaded in the six days between June 15 and June 20.
Likewise, the sharp decline of Office Mobile's position in the App Store's free list after just a week hints at a pent-up demand that was quickly satisfied.
Although rumors of Office on iOS had circulated since the iPad's 2010 introduction, they heated up last November when reports claimed Microsoft would launch a mobile version of the suite this year and tie the software to Office 365. At the time, most analysts agreed that Office 365 was the smart move because it could boost interest in the subscription concept Microsoft has bet will result in more, and more regular, revenue from its Office cash cow.
Linking Office on iOS to Office 365 would also let Microsoft avoid the Apple "tax," the 30% cut that Apple takes from all App Store sales.
Only Office 365 subscribers can use Office Mobile. Subscriptions range from the consumer-grade Office 365 Home Premium, which costs $100 annually, to several business plans that start at $150 per user per year and climb to $264 per user per year.
Office Mobile for iPhone is primarily designed for Word, Excel and PowerPoint file viewing, but users can also create new documents and, with the app's basic tools, edit existing ones.
This article, Office for iPhone downloads start with a bang, but fizzle before 4th, was originally published at Computerworld.com.
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer, on Google+ or subscribe to Gregg's RSS feed . His email address is firstname.lastname@example.org.