I believe it is safe to say that as a direct-response medium, search is top rate. We can control our ROI, CPA, and scale of effort down to the keyword and the time of day. We judge performance at the search engine, campaign, keyword group or keyword level. We test ad copy and promotional offers with the click of the mouse and look at measures such as click-through rates, conversion rates and profitability. We like this. This is good.

Now that we have successfully harnessed the power of search and feel as comfortable working and planning within its controllable metrics as we are projecting results, we come to a crossroads where media merge: the eve of Web 3.0, the convergence of search and display, social networking and user-generated content. Video. Podcasts. Gadgets and Widgets. Contextual, demographic and behavioral targeting. Local and hyperlocal. Retargeting. RSS. SMS. Mobile. Third Screen. In-game. Privacy issues and debates.

This is by no means the first time marketers have faced such a mind shift. Most recently was after the dot-com boom and bust when it became necessary, no longer radical, to move some advertising focus to the then-still-new media -- the Internet. The questions were not only why, but how? Why advertise online, and how do we know if it is working?

Search was the answer to both questions. Advertise on the search engines where people begin looking for something on the Internet. Entry cost is low - pennies actually. It's completely transparent and accountable. Changes can be applied on the fly. Testing is easy and risk is limited. Serve consumers your ad when they ask for it. Take them to a page on your Web site that gives them what they're looking for. Then watch what happens, track them right through to the credit card approval on your back-end. Repeat. Do more of what works and less of what doesn't.

And advertisers found that there was a lot that worked. We all read of 2,000% ROIs in the early days. Clients began to question why they were only getting 150% ROI when they had read about XYZ Company having a poor month with only 978% ROI as compared to previous months. Admittedly, it was a little bit ridiculous.

Even so, we continue to hold search performance to a very high standard as compared to other forms of media, both online and off. One might say we are victims of our own success and we are comfortable in that role. But in order to participate fully in the conversation of what is now the twilight hours of Web 2.0, we must shift our role and move forward with flexible and open minds toward this increasingly integrated, holistic, swiftly changing media world.

Search is a unique proposition -- this is why Google is Google and many Googlers are rich. However, search does not exist in a vacuum any more than television or direct mail does. A search engine is no longer the exclusive point of entry to the Internet for many people. Social networking sites like MySpace and FaceBook have become portals to a huge number of Web users. If the goal of the marketer is to reach the most potential customers online, thereby maximizing return on investment as a whole, it is critical to engage users throughout their online journey which, as we all become more sophisticated Web users, is increasingly not always begun at a search engine.

Traditional measures of frequency also apply online. And in the end, many people you engage with along the way will go to a search engine and type your brand or product into the search box before going to your site. Though the banner, pre-roll or mobile text ad wasn't the last touch before the conversion, it still deserves some credit. The question is, how much?

The questions still exist: Why participate and how do we know if it's working? Answers based on what we know today -- change perspective. Consider all efforts in combination and assign values to touch points. Then test, ask, track, refine, repeat.

This commentary is insightful. I recommend it to others.