The results of an iCrossing test analysis showed that paid search is good, natural search is good, but together they are better.

A debate has been raging across the industry over the last several months about the relative merits of paid and natural search and the agency practitioners of each.

Much, albeit not all, of the debate has centered on the benefits of one tactic versus search campaigns. A smaller chorus, meanwhile, has been advocating more of a synergistic approach, touting the symbiotic effects of paid plus natural search.

Advertisers, it would seem, cannot live by paid or natural search alone, so why can't they (and their devotees) just get along?

The poor proverbial horse is likely to be beyond any more beatings at this point, so a shift in the terms of the debate may well be in order. Instead of focusing on the complexity and value (or lack thereof) that agencies offering search services bring their clients, or whether search is something that advertisers should outsource or bring in-house, let's concentrate on results.

Our own internal analysis of client campaign data strongly suggests that running an integrated natural and paid search campaign (i.e. as opposed to a natural or paid campaign alone) leads to improved online performance across a number of metrics, from clicks and site actions to page views to time spent onsite.

Keep in mind that the goal of this analysis was not to prove whether paid or natural search is inherently superior in terms of producing results. Rather, it was to test whether a holistic approach (paid plus natural) would boost performance.

As a starting point, there is no doubt that paid search campaigns have a positive impact on online performance in general, so let's remove any anti-PPC or pro SEO bias right from the start.

What we found was that when a keyword was used in both natural and paid search campaigns -- particularly if it was ranked in the first three pages of natural search results -- it significantly outperformed keywords purchased for a paid search campaign (but not ranked in the first three pages of natural search results).

This may seem axiomatic to longtime search practitioners or obvious to others from an anecdotal perspective, but consider the results. In our test, when we incorporated natural search into an existing paid search campaign and compared its performance to the performance of the paid search campaign alone, clicks soared by 92 percent; the number of site actions rose by 45 percent; page views increased by 44 percent; site visitors climbed by 41 percent; and time spent onsite went up 39 percent.

The conclusion was that paid search is good, natural search is good, but together they are better -- the proverbial "one plus one equals three."

Marketers looking for an edge, take note.

From the advertiser's perspective, the goal of any campaign in any form of media is to get maximum results for minimal cost. Whether advertisers using search to achieve online visibility and drive customer actions decide to outsource their campaigns to a specialist agency or entrust the work to internal experts, this goal doesn't change. Therefore, it matters little whether paid search or search engine optimization is rocket science or child's play. The question is which tactic is most effective at what point in a campaign, and how can they be used together to produce the best overall results?

With increasing evidence across the board that marketing is only becoming more integrated rather than less (traditional digital agency consolidation, restructuring of client-side marketing organizations, shifts in media consumption habits due to the blurring of channels), now seems like a peculiar time to argue that one of two closely linked tactics is vastly superior to the other.

These days, most people would be hard pressed to point to any under-worked search professionals on either the agency or client side of the business, suggesting that paid-natural cannibalization is a minimal threat at this juncture.

It may well be the case that as marketing becomes more of an integrated discipline, the relative importance of practitioners of any one aspect of it will decline. But those are the breaks, as they say.

The road ahead heralds more collaboration, not less, so the sooner we all get on the same bus, the better off we'll be and the greater the benefits will be for our clients.

Noah Elkin, Ph.D., is vice president of communications at iCrossing. Read full bio.