In a past life, Microsoft relied heavily on business interest for its Windows Mobile platform with the consumer taking a back seat in priorities. Today that has all changed and one of the areas Microsoft is counting on is word of mouth to generate interest. For that to work, the OS will have to be good. Very good.Steve Ballmer was interviewed by Nick Winfield for the Wall Street Journal on Windows Phone 7, which will be formally announced next Monday. Mr. Winfield asked if there would be an immediate move upwards of Windows Phone's share. Ballmer deflected the question stating that he wasn't going to make forecasts, but said that two key items in its success will be advertising and word of mouth.

Advertising is a no brainer. Microsoft has committed half a billion dollars to Windows Phone's advertising and marketing campaign, which is a serious commitment, especially compared to previous campaigns for Windows Phone which was often limited to posters in airports and subway stations or on the side of busses.

Word of mouth though is priceless. To be successful in that, the platform will have to perform nearly flawlessly in what it promises to do and do it as well if not better than the competition. There have been a lot of positive reviews of the device. The browser is capable and fast and the user interface is butter smooth with nary a sign of a stutter regardless of what it is asked to do. It is all the more impressive that most of these reviews are with an unfinished OS on prototype hardware. The OS has since been finished, but I haven't seen any final hardware reviews.

The true test will be when it ships. A poorly designed platform, no matter how smooth, won't get very far. What is telling though is Ballmer and Microsoft get how important positive word of mouth is on a platform like this. It may seem obvious in hindsight, but for Microsoft, it is a key shift in how they view their entry into the mobile phone business. It isn't about pushing devices out through IT departments. It is about the product being pulled off of the shelves by consumers.