Simply put, Time-Warner's (NYSE:TWX) track record on acquisitions is a disaster. So shareholders were probably -- rightfully -- squeamish to learn that, through its AOL division, it will buy Advertising.com. Is this the proverbial sign that the market has peaked for search engine advertising?

Advertising.com is essentially a reseller of online marketing products from providers like Yahoo! (NASDAQ:YHOO), FindWhat.com (NASDAQ:FWHT), LookSmart (NASDAQ:LOOK), and Google. The company does have its own broad suite of software tools to help clients manage their online marketing campaigns -- such as with data mining, optimization, performance tracking, targeting, and so on.

Advertising.com has a sterling list of clients, such as BMG and Wal-Mart (NYSE:WMT), who like paying for effectiveness, not fuzzy things like branding and banner impressions. Last year, Advertising.com generated $12.1 million in profits on $132 million in revenues.

But AOL's acquisition of Advertising.com raises a conflict problem. Advertising.com is known as a search engine marketer (SEM). The purpose of an SEM is to get coverage in many channels. But since AOL is a marketing channel, might it be tempted to push customers its way?

This could scare clients into jumping ship to another SEM, such as ValueClick (NASDAQ:VCLK), 24/7 (NASDAQ:TFSM), or DoubleClick (NASDAQ:DCLK).

In fact, the Advertisng.com acquisition could scare the search engines, as well. After all, an SEM has access to lots of competitive intelligence of the many search engines. Might this information be used by AOL's own search initiatives?

Advertising.com recently filed to go public. It is interesting to note that the shareholders are taking $435 million in cash -- not stock in Time-Warner. Management of Advertising.com surely realizes the challenges and sees this as an opportunity to cash out.

Fool contributor Tom Taulli is the author of The EDGAR Online Guide to Decoding Financial Statements. He owns shares in FindWhat.com.