We know what you’re thinking: “I understand my customers. They’re exactly 25-49 years old. They’re male. Or female. They make a lot of money, unless they don’t. Their buying habits are motivated by their children, unless they don’t have any. They’re brand-loyal, although value-conscious. They like reality shows and Lady Gaga and NASCAR and gardening. See? A nice clear picture.”

Sorry, but all you’ve got there is a demographic. Those were fine during the days of the :30 TV spot and the year-long print campaign. Customers had to accept that they were the “mass” in mass-marketing. But not anymore. They have become individual consumers, with individual desires and motivations. The great news is that they’re trying to explain this to you. With every text, comment, click and tweet, they’re painting their own picture: This is ME.

Perhaps you heard: newspapers are dead, TV is dead, books are dead. From these facts alone you’d think no one is reading or watching. But that’s ridiculous. Since 2005, online newspapers have added 30 million new readers. YouTube adds more content in two months than the Big Three networks broadcast in their entire histories.

Consumers are consuming more than ever. But they’re doing it in highly fragmented and individuated ways. They’re moving through a sea of information, making hundreds of decisions about what to read, what to watch, what to recommend and what to buy. For brands, this is great news. There are more opportunities than ever to influence behavior. But you have to match your brand promise to the customer need. And you have to know when, how and where to do it.

Throw away your marketing calendar. You can’t schedule relevance. These days, relevance happens in the moment. Your brand has to shift from the big-splashy-launch mentality to the what-do-we-need-to-say-today mentality. It needs to adjust to cultural memes, breaking news, consumer attitudes and whatever the heck your competitors are up to. It’s time for your brand to live in the now.

The good news is that once you abandon the brand-centric habit of planning your campaigns 12 months in advance, you open yourself up to amazing new ways to monitor, measure and adjust the performance of your marketing efforts. Something’s not working? Kill it. Consumers flocking to a new virtual space? Go there—right now. Don’t study channels. Study context. What are customers feeling and thinking right before they come across your message? What matters to them at that moment?

People act differently in different environments. Want proof? Offer someone a beer…in church. OK, now offer someone $5 off a pair of movie tickets…while he’s driving to work. Part of adapting to the needs of your customers is thinking about where they’ll be when they interact with your brand—and shortening the amount of time your message has to survive before it can be turned into action.

Out-of-home advertising has already started to master location-based messages (for instance, restaurants and hotel ads running on the screen in the back of a taxi). With smart phones and proximity marketing, you can take it a step further. Your messages can be inserted strategically into the flow of a consumer’s day, at the time and the place when he or she is most likely to take action. Don’t sell movie tickets to a guy headed to work. Sell them at 3:30 pm, when he’s out grabbing an afternoon coffee, trying to figure out his evening plans.

The human brain is a big fat mystery. You drop in an idea, pull the lever, and the craziest contradictions pop out. People tell you they want to save the environment, yet they buy SUVs. They tell you they want to live a healthy life, but they eat bacon on everything. Clearly, we can’t rely solely on what consumers tell us. We have to study their unconscious motivations. We have to learn how the brain gets where it’s going.

When consumers are plopped into a new physical or digital landscape, they immediately begin to draw on a deep reservoir of beliefs, experiences and information. They follow a “cognitive map” that allows them to find themselves within the broader context—this is where I am, this is what I think, this is what I should do next. By analyzing the way your customers “move” through certain environments—retail spaces, web interfaces, surveys, custom apps, etc.—you can fine-tune brand interactions to influence the way they learn and make decisions.

The marketplace is full of companies that just don’t get it. The punch-drunk brands of the old world order. Bloodied and bewildered, they stagger onto rooftops, sounding their self-centered yawps to an indifferent world: “Introducing our new innovation! A revolution in personal grooming! Hello? Is anyone out there?” Those brands are failing because they’re presumptuous. They presume people give a crap.

Advertisers have the freedom to interact with consumers in more places, at more times, in more personal ways than ever before. But with freedom comes responsibility. If you create an ad that interrupts someone when she’s on Facebook, posting pictures of her children, you better have something relevant to say. You aren’t using public space or public airwaves anymore. You’re a guest in her private digital home. If you barge in bragging about yourself, leaving scuffmarks on all the furniture, you’ll never be invited back.

Goodbye mass marketing. Goodbye one-size-fits-all. Goodbye Me, Me, Me. Looking back, that was always your problem, wasn’t it? You only cared about yourself, about what your brand “stood for.” Like it was a soldier in a war against our better judgment. Did you ever listen to us? Did you ever talk with us, instead of at us? Everything is changing, but you stay the same. You just stand there, with your big fat headline and your big stupid logo, glaring out at the world, totally deaf, totally oblivious. Why can’t you adapt?