Believe it or not, digital marketing is reinventing itself once again!Yes, we've all seen this movie before&#8230; the invention of the browser, the launch of third-party ad servers, the advent of "portals," the rise of search. And now &#8211; the ascent of real-time, audience-based targeting.Previous innovations have remade the online ad industry in ways not always imagined when their first ripples hit. But real-time targeting promises to be the most far-reaching reinvention of all.When I joined the Internet "industry" in 1994, the online universe consisted of such services as Prodigy, Compuserve and the fledgling AOL. Marc Andressen had just invented the Mosaic browser (later Netscape).As a 30-year-old former brand manager, I thought "online" was the most exciting thing I had ever seen. The first time I logged on to AOL, then mostly text on a 2400-baud modem, I called my wife (also a brand manager) and said "you've got to see this&#8230; it's going to change everything."OK, it didn't change everything&#8230;but it sure changed lots of things. It spawned a new industry and new ways for marketers to interact with, service and advertise to their constituents.Such revolutionary change is here again.Today's disruptive technology is the online ad exchange. More than just a way for marketers to bid on ads, it separates ads into three independent components:1. Audiences2. Content3. Audience dataThe ad exchange allows marketers to manage each of these components independently -- to mix and match them to meet marketing needs on a case-by-case basis -- and to better meet the needs of consumers.Let's go back to 1994 again. I joined a tiny little company, Modem Media, which ran interactive promotions. Our platforms were telephone and Prodigy. That year we bought the first paid ads ever on the Internet via Wired magazine's Hotwired.Soon, we were running ads on a dozen Web sites and picking through their printed log files to determine if the ads ran and how many people saw them. Then I met Kevin O'Connor. He had started IAN, the Internet Advertising Network, and he proposed delivering ads to multiple Web sites from a central server and counting the deliveries. Imagine! Each connection, and each user's browser, would be tracked&#8230; with ads ultimately targeted to individuals.The Internet Advertising Network became DoubleClick, and two years later delivered to us what was probably the Internet's first one-to-one targeted ad.Fast-forward to 2010. Online advertising is realigning on the waves and ripples of real-time audience targeting, ad exchanges and real-time bidding. As a result, scale is increasing for Data companies like Excelate, Datalogix and Blue Kai, ad agency trading units like OMG Trading Desk and the adexchangeslike RMX and the ADX.Today's online publishers are thinking about how to effectively realign their business models to compete more effectively in a landscape where ad buyers have more information than the publishers themselves about their own audiences.My company, [x+1], is in the middle of it all, working to enable real time audience targeting on the exchanges, and for any digital touchpoint.What does this mean for marketers? Does it matter to giant advertisers? Or to the millions of local, small and mid-tier companies previously responsible for the growth of search?Yes, it does. Because the effect we're already seeing in display advertising is just a ripple &#8211; we're likely on the crest of a very big wave that will take us far beyond display and far beyond ad exchanges.Such growth raises pertinent questions.Will real-time audience targeting inject data into every interaction online?Will every digital touchpoint &#8211; display ad, Web site interaction, e-mail, online video or mobile app &#8211; be aware of its users?Will marketers, as they recognize their customers online, use all these touchpoints for service and relationship enrichment?Will data and one-to-one technologies be so effective that integrated digital marketing becomes the center of every single marketing plan?A "yes" answer to all these questions is not only possible but our vision at [x+1]. That's why we're hosting today's NexTargeting Summit (http://nextargeting.com) in New York City. Not just to talk about real-time audience &#8211; as exciting as it is &#8211; but to explore how this latest reinvention opens new possibilities for the entire online marketing industry.After nearly two decades of constant change in online marketing, no change has excited me more. Now is truly the greatest time ever for our industry.John Nardone is Chairman &amp; CEO of X+1. He can be reached at email@example.com.