Richard Driehaus, the chief investment officer at Driehaus Capital Management LLC, specializes in aggressive investing, so it makes sense that he has a big position in Google (NASDAQ:GOOG). He also bought a 1% stake, and had his firm purchase another 8.1%, of another fast grower in the online advertising space: 24/7 Real Media (NASDAQ:TFSM).

While 24/7 is not growing at Google's rapid rate, its results are nonetheless impressive. In the fourth quarter, revenues increased 52% to $41.7 million. Net income was $1.4 million, or $0.03 per share, which was up from a net loss of $2.8 million, or $0.06 per share, in the same period in 2004.

24/7 was one of the early players in the online advertising market. Its core market used to be ad-serving, a technology that delivers banner ads across websites. This was a very lucrative business until the dot-com bust; indeed, 24/7 nearly went belly-up several years ago.

After a painful restructuring period, 24/7 is now a much different company. It has a leaner cost structure and new service offerings that meet advertisers' dynamic needs. In my opinion, companies like 24/7's ability to offer them a full-blown advertising package, instead of sticking merely to the increasingly commodified ad-serving market. Paid search is critical area for 24/7, in which the company helps its clients effectively market on properties like Yahoo! (NASDAQ:YHOO), Google, and Microsoft (NASDAQ:MSFT). To this end, the company has implemented an end-to-end offering for search marketing: campaign planning, keyword research, copywriting, bid management (for keywords on the search engines), landing page strategies, and monitoring of results.

The recent acquisition of Decide Interactive helped 24/7 piece together such a complete system. During the fourth quarter, the company's Search Solutions segment saw revenues surge by 141% to $16.4 million.

Moreover, as online advertising becomes more mainstream, advertisers want global solutions. During the past year, 24/7 has set up offices in Tokyo, Rome, and Hamburg. There's also a joint venture in Japan with Dentsu, Asia's largest ad agency, to capitalize on the search market. In light of this, it's hardly shocking that a significant chunk of 24/7's revenues come from international operations.

With the continued shift of ad dollars to the Internet, companies will need the sort of value-added services and technologies that 24/7 offers. True, the company has fierce competition from companies such as aQuantive (NASDAQ:AQNT). But with 24/7's comprehensive offerings -- and global footprint -- there should be more than enough business for the key players to grow at a healthy clip.

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Fool contributor Tom Taulli does not own shares mentioned in this article.