The big gamble starts October 7th. Sprint just updated their website with an advertisement for pre-orders on the iPhone 4s. Eyes of the tech world and Wall Street will be watching the pre-order numbers closely as Sprint has “bet the farm” on the iPhone; their plans to buy 30 million iPhones over the next 4 years for $20 billion has already worried investors and drawn criticism. Editorial Note: As we recently mentioned, their ability to take a piece of the iPhone market from Verizon and AT&T hinges on their ability to promote their unlimited data plan as a differentiator. The ad, pictured above, says nothing about it. Clicking through shows a brief mention of the plan in a box to the lower right (the least viewed portion of a web page). For them to succeed, they MUST expose the unlimited plan as much as possible. So far, this isn’t doing it.