It was back in February when Google (NASDAQ:GOOG) passed eBay (NASDAQ:EBAY) to command the market-cap crown of Internet stocks. They were passing ships at the $50 billion buoy. They have continued going separate ways, with Google now commanding a market capitalization closer to $60 billion while eBay starts off the week as a humbled $42 billion corporation.

When I compared the two stocks back in February, it appeared as if the more seasoned eBay offered the best value looking back, but Google was the cheaper play going forward. Adding more fuel to that disparity were last week's earnings reports. The leading online auction marketplace raised its 2005 profit forecast to a range of $0.71 to $0.73 a share, but that was still lower than what analysts were expecting for the year. Meanwhile, Google has Wall Street revising its targets higher after its third consecutive market thumper.

Do you think there is no way that Google can possibly be cheaper than eBay? I know more than a few of you may be thinking that Google's valuation is wacky and that eBay is now the bargain. I beg to differ. I will even show my math.

Now that eBay, which is a Motley Fool Stock Advisor recommendation, has made its latest guidance clear, we can value the company based on this year's earnings multiple. The stock is at $31.51, well off the price that it was fetching when it traded just shy of a split-adjusted $60 as the year began. At the current price, eBay is trading between 43 and 44 times this year's projected profitability.

Then we have Google. The company earned $1.29 a share this past quarter. While one can argue that certain favorable tax charges inflated that figure or that stock option compensation deflated it, the difference is pennies in either direction.

Now, Google does not provide earnings guidance. That goes a long way toward explaining why Wall Street has underestimated the company's earnings ability, by a lot. Yet we do know that this is not a seasonal business. Sequential gains should continue as long as the company's bread-and-butter paid-search business proves resilient. But let's assume that $1.29 is as good as it gets. That's highly unlikely, but if all Google does is ape those results for the rest of the year, it will have earned $5.16 a share for all of 2005 -- or a forward multiple of 42. Yes, cheaper than eBay.

In Google, you have a company whose earnings grew more than fivefold, accompanied with a 93% advance in revenue. For eBay, it was a 28% gain in net income while the top line rose by 36%.

If you think this is just a case of the smaller company simply having an easier case for growing faster, think again. Consider that eBay earned $256 million for the period while Google came back with $369 million. What about real earnings, you say? Well, for the March quarter, eBay produced $289.4 million in free cash flow. Google? It racked up $387 million in free cash flow.

Google's potentially fatal flaw -- its dependence on search advertising -- can't be emphasized enough. But Google's lapping eBay in the market cap space in recent months was no accident.

Google has passed by other companies, too, in its brief publicly traded life. Weeks before Google came public with a proposed market cap of just over $20 billion, shares of (NASDAQ:AMZN) peaked at $23 billion. Yahoo! (NASDAQ:YHOO) has been a healthy performer, but at $50 billion, it, too, found Google flashing the high beams in its rearview mirror. So, yes, Google is pretty fast, but it's earned the right to live large in the passing lane.

More snapshots of passing ships in the dot-com harbor:

Longtime Fool contributor Rick Munarriz is a satisfied eBay and Google user. However, he does not own shares in any of the companies mentioned in this story. The Fool has a disclosure policy. Rick is also part of the Rule Breakers newsletter research team, seeking out tomorrow's ultimate growth stocks a day early.