Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of mobile advertiser Millennial Media (NYSE:MM) rose as much as 12% today after posting strong improvements across multiple earnings metrics. The company's fourth-quarter and full-year EBITDA guidance for 2012 also came in ahead of analyst projections. Shares have settled into a gain of about 7%, suggesting that investors have tempered their optimism to some degree.

So what: Millennial Media saw revenue from existing clients more than double in its third quarter, and total revenue increased 88% year over year to $47.4 million. The company's adjusted EBITDA was $2.1 million, a nice improvement from the second quarter's $0.7 million adjusted EBITDA loss. However, bottom-line GAAP results showed a net loss of $0.02 per share, which is at least a much narrower loss than the year-ago quarter's $0.09 GAAP EPS loss.

For the upcoming quarter, Millennial expects revenue in the $61.5 million to $63.0 million range and adjusted EBITDA from $3.0 million to $3.5 million. Full-year guidance anticipates revenue of $181.0 million to $182.5 million and adjusted EBITDA in the $2.0 million to $2.5 million range.

Now what: Analysts had expected $179.8 million in full-year revenue and a full-year EPS loss of $0.03, so these results indicate that Millennial Media is forging ahead in the highly competitive mobile-ad space without sacrificing its drive to profitability. Millennial Media could still be bought out by one of the industry titans, and it could also reach profitability next year if the positive momentum continues. It may not be a cheap stock, but after this performance, it deserves a closer look.

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Fool contributor Alex Planes holds no financial position in any company mentioned here. Add him on Google+ or follow him on Twitter, @TMFBiggles, for more news and insights. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. Try any of our Foolish newsletter services free for 30 days. The Motley Fool has a disclosure policy.