As Yahoo! hits another low, its relevance fades

Yahoo!'s (NASDAQ: YHOO) shares hit another multi-year low, trading down to $15.54, off by more than half from its 52-week high of $34.08. That high was driven by a buyout offer from Microsoft (NASDAQ: MSFT), but Yahoo! now trades well below the level where it changed hands before Redmond came calling.

Yahoo!'s market cap is below $22 billion. By some estimates its ownership of Yahoo! Japan and Chinese e-commerce company Alibaba are worth $10 billion. That means that Yahoo!'s core business trades at only two times sales, a remarkably low figure.

Two fears have pushed Yahoo! down. The most obvious is that its share of the search market in the U.S. has fallen to about 20% and continues to drop. It may form a partnership with Google (NASDAQ: GOOG) to push up its revenue in this arena, but the deal is being challenged by antitrust authorities.

The major reason behind Yahoo!'s drop is one that would tend to push the shares down more over time. Wall Street has believed that internet display advertising, Yahoo!'s key revenue business, would continue to grow at rates of more than 20% for the next several years. Recent evidence is that many marketers do not consider online display ads to be very effective, maybe even less effective than TV. Some large internet firms have watched their growth rates drop to single digits.

Yahoo! may be up against a problem that has no easy solution.

Douglas A. McIntyre is an editor at 247wallst.com.