Monster.com (NASDAQ:MNST) was tough enough to survive the dot-com bust, and it certainly seems to be lumbering along pretty darn well these days. The online job-search specialist released its fourth-quarter results Wednesday, and the stock's increase upon the news seems to have given investors reason to think that it's a keeper.

Monster.com reported a 49% increase in fourth-quarter net income to $36.5 million, or $0.29 per share, with revenues increasing 24% to $266.6 million. (Earnings from continuing operations were $0.28 per share.) For the year, Monster increased cash and cash equivalents to $320.3 million, and pared down debt by 25.6% to $47.1 million. Furthermore, the company generated free cash flow of $181.8 million, up 139.5% from the same period last year. The company has also been busy repurchasing stock.

Monster.com's current success is hardly surprising. For one thing, employment classifieds are increasingly migrating to the Web (you've likely heard of the tough times for newspapers), and the employment outlook has significantly improved lately. Meanwhile, Monster's strategic moves into international markets also seem to be paying off; the company said that Nielsen/NetRatings' November data ranked Monster as Europe's most visited site. Monster's also trying to get its foot in the door in the hot Chinese market.

Monster shares were up 16% in recent trading, whereas a year ago, the company scared investors. But noting Monster's forward P/E of 40, I couldn't help pondering the possible risks that could slow down Monster's fortunes in the future. There's really quite a daunting list of competitors, including Web-based employment sites like Yahoo!'s (NASDAQ:YHOO) HotJobs and CareerBuilder, a joint venture among newspaper companies Gannett (NYSE:GCI), Knight-Ridder (NYSE:KRI), and Tribune (NYSE:TRB).

There's also Craigslist, which has caused newspapers some pain, and the impending final release of Google's (NASDAQ:GOOG) Google Base. The latter may not be ready for prime time, but I'd say that once it is, everybody in the space had better look out. For the purpose of this piece, I tested it out a bit, and it looks seems Google's existing search elements -- for example, returning job advertisements while pinpointing those jobs' location on a map. Pretty nifty -- although I was a little creeped out by the fact that it seemed to already know I live in Alexandria, Va. What else does it know?

At any rate, although job advertising's print component may be a poor comparison to the possibilities on the Web, I believe Monster lacks a sufficient moat to protect it from some very capable competitors. Monster.com may have a lot of elements in its favor right now, but shares purchased today might not end up being a monster of a deal.

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Alyce Lomax does not own shares of any of the companies mentioned.