If there was any doubt of a pent-up demand for Microsoft Office on the iPad, the weekend's performance cleared things up.
Three days after launching iPad version of Word, Excel and PowerPoint, Microsoft owns four of the top five slots in Apple's iTunes iPad app store. The previously launched OneNote sits in fifth place. That's not just in the productivity category, Microsoft's apps are now the top ranking download across all categories.
Cynics may argue that success is down to curiosity and the publicity Microsoft picked up with the announcement. Perhaps.
Yet, being at the top of this table is an achievement by any standard. Having four of the top five is outstanding.
The important point is that suddenly Microsoft is relevant again in a way it hasn't managed until now. Microsoft's Surface tablets are a nice re-imagination of the laptop PC, but they haven't set the world alight. Windows Phone 8 is a great smartphone OS, but it still languishes as an also-ran. iPad Office is a triumph.
Microsoft had to wait a long time for this moment. If anything it underlines the wisdom of retiring Steve Ballmer and installing Satya Nadella as the new CEO. His tenure is off to a dream start.
It would be interesting to see how many new Office 365 licences Microsoft picks up this week.