Experimenting with capitalization (in more ways than one), Yahoo CEO Jerry Yang wrote his company's shareholders to explain why he believes Microsoft isn't assessing Yahoo's value fairly.

Yahoo has one of the world's most recognized brands, it has partners whose contributions can't be matched, and it has a tremendously positive cash flow, and it has a world-class search engine infrastructure, argued CEO Jerry Yang in a widely distributed letter to Yahoo shareholders yesterday afternoon. All four of these factors would be diluted if the company were simply to be absorbed as another of Microsoft's brands, he directly implied, referring to Microsoft only in his opening paragraphs.

"These assets -- our brand and its audience, our relationships with marketers, our financial strength, our technology, and our strategic investments -- are the core of our value and our leadership position in the industry," Yang wrote. "We have a huge market opportunity, and are uniquely positioned to capitalize on it."

To that end, Yang did go so far as to mention one explicit goal: He intends to grow the total number of visits to Yahoo-hosted properties by a steady annual rate of 15% "over the next several years" -- a figure also quoted a few weeks ago by Yahoo President Susan Decker during the company's quarterly conference call, just two days prior to Microsoft's bid.

Yang's point that Yahoo is already the Web's leading display ad distributor, has evidence to back it up. On the day of the Microsoft bid, comScore projected that Yahoo-hosted sites were responsible for delivering 18.8% of all display ads to US-based households, offices, and classrooms, with an average of 20.5 ads shown to each visitor, per visit. Coming in a close second were Fox Interactive sites with 16.3% of the nation's deliveries, but a staggering 47.5 average displays per visit.

But Yahoo has made no secret of the fact that it isn't happy with the way comScore assesses its visitor numbers. As Decker stated on the earnings call, her company would like to trust comScore's figures, but it feels they're too aggregated to point to real trends.

"We are looking at third party services such as comScore to assess unique users or time spent," Decker stated on January 29. "The aggregated figures may not tell the story of what's happening and the key value creating starting points for consumers and advertisers. Our internal log show that the metrics we've discussed with you in the past such as uniques and page views continue to grow in the double-digits in Q4 with unique users now topping 500 million and page views above 4 billion per day."

Meanwhile, comScore's figures tend to show Yahoo coming in a little shy of half a billion visitors, with about 133 million of those coming from the US. A Compete.com estimate last fall projected Yahoo's unique visitor growth rate at about 11.2% annually, several points shy of Yang's goals.

Elsewhere in his stockholders' letter yesterday, Yang made mention of Yahoo's key acquisitions in the past year, including Blue Lithium and Right Media, in an effort to build out its Panama platform and its advertiser services -- features which Microsoft appeared to indicate it wasn't really interested in.

"Today, Yahoo is a faster-moving, better-organized, more nimble company than it was just a few months ago," Yang concluded. "We have redeployed our resources to drive Yahoo's key strategic priorities, taking important steps to streamline our organization and close down or scale back businesses that don't support these critical growth initiatives. The fact is that we are well on our way to transforming the experiences of Yahoo's users, advertisers, publishers and developers -- an important shift that is at the heart of our plan to create stockholder value."