Tumblr Chief Executive David Karp has focused on building the company's user base for its minimalist blogging platform while leaving for later the question of earning money.

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As Android is free, and the current number 2, iOS, is not even available for licensing, any of the Android makers who launches product on other platforms migrates to a tiny system which has under 4% sales, and for any new platform, even less in installed base.

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He likens the situation to the early days of iOS, when smart developers recognized that it was a platform worth building for despite the then-small user base.

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This may however be offset by the dwindling base of Nextel subscribers who have also been a big source for the Sprint platform net adds in recent quarters.

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As the digital base expands, it will become easier for the company to market these advanced services that require digital platform.

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With over 26, 000 restaurants in North America on the OpenTable platform and an installed base of equipment in each, not only is it a hassle for restaurants to decamp from the service, but also it would be very challenging for the next OpenTable to successfully enter the marketplace.

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