Until not so long ago, marketing’s role hadn’t changed much from the age of the “Mad Men,” the hit TV series about the 1960s. Marketing was there to drive brand awareness, to create interest in the company’s products and services, to make people want to buy. Vitally important, sure, but that was as far as it went. What went after that was someone else’s problem – sales, service, operations, manufacturing, logistics – all happening “over there somewhere.” Downstream. Marketing was decoupled from the supply chain, in an ivory tower. Marketing’s IT was largely separate, too.

For example, in a major European manufacturing company that I worked for, marketing had Macs, while the rest of the company had PCs – and in those days it was difficult to link the two. I always felt this was indicative of marketing’s cultural and functional separation, and I don’t think it was untypical of the time.

Today, things are looking very different. IT caused the change, and IT must respond. In the age of the Internet, and social software in particular, marketing is now creating demand through websites, through campaigns on Facebook and Twitter. And here’s the difference: when people see things on Facebook – either on the company Facebook page or a friends’ recommendation – or they see an advertisement or article on a website, they want to buy. Now.

So marketing has to tie directly into the supply chain. People want to go from a Facebook site to a webpage where they can buy – they want to know what it costs, whether it’s available and when it can be delivered. Marketing IT is no longer separate; it needs to be an integral part of the supply chain, as well as linking tightly to the other two pillars of CRM (sales and service).

Recognising this, last month IBM held a strategic marketing event aimed at CMOs and CIOs jointly. It was explicitly addressing the profoundly changed relationship between marketing and the rest of the business, and how IT is at the heart of that change. For IBM, this is opening up a whole new audience for its products and services.

Putting its money where its mouth is, IBM’s CEO Ginny Rometty and Marketing SVP Jon Iwata both spoke about what IBM itself was doing, internally and with its customers – as well as, of course, talking about its related offerings such using as Big Data offerings to facilitate sentiment analysis. Perhaps more powerful were keynotes from execs that “get it” – one global telco’s CEO spoke of moving from mass market offers to direct engagement, and a large retailer’s Marketing & Digital Officer pointed out that his workforce, through its social connections “can reach two-thirds of Britain.” Actually, that’s a little scary. WPP’s Sir Martin Sorrell spoke of “mass personalization.”

There can be no doubt the IT-driven shift in marketing’s new role is here to stay. So IT is in the front line. It must cooperate with marketing, and indeed IT may consider marketing to be its most important internal customer for the next few years. Expect other service and technology providers to be very vocal about this in the coming months. Some, like Adobe and Oracle, are already making much of this and we will see much, much more.