To quote Carol Bartz, the CEO of Yahoo, “never’s a long time”. But that’s what Jeff Bezos promised today at Amazon’s annual shareholder meeting, when asked about Kindle sales data: “I’m not sure we will ever reveal all the numbers…Our point of view is that there is a competitive advantage to keeping the numbers close,” he said, quoted here on Marketwatch.

To continue with the tease, he said he checks Kindle sales data daily, and “the data we have shows us that this is turning into something special. So I beg your indulgence on the question of how many Kindles have been sold.” Thus giving tons of fodder, speculation and quarterbacking to analysts and bloggers about the real impact of Kindle on the book industry, and the company’s bottom line.

What Amazon (NSDQ: AMZN) has officially said till now is that where a Kindle version of a book is available on its site, it makes up for almost 35 percent of total sales of that book, a figure which astounded a lot of industry observers when it came out earlier this month at the launch of Kindle DX. That, and oh, this illuminating factoid, from Bezo’s annual report letter to shareholders: “We’ve received thousands of feedback emails from customers about Kindle, and – remarkably – 26% of them contain the word ‘love.’”

Analyst estimates on Kindle sales data have varied widely, with some estimating that the company may have already sold half million Kindles in 2008, and that it may touch 1 million mark this year. Collins Stewart analyst Sandeep Aggarwal came out with a note last week estimating that Kindle will earn Amazon upwards of $300 million in revenue this year and $70 million in profit, growing to $1.6 billion in revenue and at least $400 million in profit by 2012.