If history serves as a gauge, online marketers won't feel the full brunt of the current economic crunch until early next year. Here's what you should expect to see in the coming months.

The worsening economy, ongoing credit crunch and see-sawing stock market have everyone understandably worried about what the future holds. As we try to grapple with the potential fallout and its impact on our industry, our businesses and our individual jobs, examining both the past and present may be instructive.

The most recent economic downturn, precipitated by the dotcom bust, began with the Nasdaq correction in March 2000 and really hit its stride by the end of the year. A look back at industry surveys by PricewaterhouseCoopers and the Internet Advertising Bureau shows that the decline in ad revenues -- a "trailing indicator," as many analysts have pointed out -- did not begin in earnest until the first quarter of 2001, when budget cuts started to go into effect. Online ad spending then proceeded to drop quarter over quarter and year over year for the remainder of 2001 and all the way through the third quarter of 2002, posting a 12 percent decrease for 2001 and a 16 percent fall for 2002.

By the fourth quarter of 2002, things began to turn around. Although spending for the quarter showed a modest (4 percent) year-over-year decline, it posted a 9 percent quarter-over-quarter increase. With the exception of a minor blip in the third quarter of 2004, we saw uninterrupted quarter-over-quarter growth through the end of 2007. Spending dropped 3 percent in the first quarter of this year and was flat in the second, while year-over-year growth slowed relative to the same period in 2007.

Not all online advertising segments were affected equally by the most recent downturn, but what the industry did witness in this period was widespread cannibalization, with paid search in particular emerging as a bigger slice of a shrinking pie, largely at the expense of display advertising and sponsorships. In 2001, these two formats accounted for more than 60 percent of all online advertising revenues, versus just 4 percent for search. By the end of 2003, when the industry had returned to healthy levels, search represented 35 percent of total spending, compared with 31 percent for display and sponsorships combined.

Search today accounts for roughly 45 percent of revenues, making it by far the biggest piece of a much larger pie. Search is currently a little more than double the size of display, and that's not even counting agency fees for search engine optimization work, which have also grown considerably since 2000. The ascendancy of search should not obscure the fact that online advertising in general is far more significant today than it was at the beginning of the decade. Spending on all formats has more than tripled, as has online's share of total advertising, which now stands at approximately 9 percent.

There has been some healthy debate among my fellow iMedia columnists, as well as many experts around the industry, about exactly what impact the current downturn will have on digital marketing. In 2001, the internet economy was disproportionately affected by the slump, as investors developed a sudden aversion for the overcapitalized and underdeveloped companies they had flocked to only years earlier. Today, all signs indicate the troubles to be both broader and deeper. In many ways, the current situation brings to mind the oft-repeated Eisenhower-era adage that "as goes General Motors, so goes the nation." Substitute Google for GM, and the old saw largely holds true. In market capitalization and certainly in profit -- if not in total revenues -- Google is now bigger than GM. Its performance may not (yet) determine the state of the nation, but it is undoubtedly the bellwether of the online world.

If history serves as a gauge, we won't feel the full brunt of the current downturn until early next year, and the impact, when it does come, will be uneven. It's a safe bet that advertising spending overall will stagnate if not shrink in the near term, and already troubled segments like print will suffer even more. The lack of insight into Google's potential future performance limits the degree to which we can project the ongoing success of search in a declining market. However, recent research appears to favor results-driven media over experimental formats.

The legendary Satchel Paige once said, "Don't look back. Something might be gaining on you." In a sobering moment when the growth we've come to expect grinds to a halt, we need to heed Paige's advice. Achieving results and collectively proving our worth are the ways to prevent the past from catching up.

Noah Elkin is vice president of corporate strategy for international search-inspired digital agency Steak.