This is a guest post by Jeff Hasen, a mobile strategist, chief marketing officer, and founder of consultancy Gotta Mobilize, which advises brands around the world.

Pick up your mobile phone. You're staring at the 21st century love affair.

As long-time adman Hank Wasiak, the former vice chairman of McCann Erickson, puts it, people don't have a relationship with their television set or their computer, but they do with their mobile phone. The intimacy between a human and their smartphone is as intense as we've ever witnessed.

The central question for businesses active in the mobile space: Can marketing find a place in that relationship--or is three a crowd?

The data marketers see and the feedback they receive paints a clear picture of mobile users' expectations: They want to be understood, while simultaneously fighting hard to maintain their privacy. Kind of like a teenager.

So what is a brand to do? In short: be courageous. Find ways to create value, take care to be neither intrusive nor creepy, and always look to get better.

For my new book The Art of Mobile Persuasion, I spent a year talking to some of the most courageous mobile marketers working today. The insights from Expedia, Lowe's, REI, Google, ESPN, and others provided both tips and turnoffs--and they're applicable to anyone seeking to create a better kind of consumer engagement on the device we love more than any other.

First, the turnoffs. Here are five words to describe the brands that are failing on mobile:

1. Selfish. If you're reaching out to mobile users, you had better be answering their needs and desires, not simply fulfilling your own.

Jonathan Stephen, who drove innovative mobile programs at JetBlue, points to the greed of some brands that seek to needlessly uncover such inconsequential details as how many sweeteners wireless owners put in their coffee and if they use Splenda or Truvia. Unless you are an artificial sweetener company looking to grab more market share, this information is extraneous and prying.

2. Illogical. Common sense deserves more credit than it gets.

For example, why create only an iPhone app if your customers are mostly or completely Android owners? That's just dumb. But it happens. Smart marketers rely solely on their own business's customer insights to power their programs, and to address the specific behaviors exhibited.

3. Timid. Seize the day.

Wasiak has been marketing for more than five decades. He is among the most accomplished in the field, but when he looks in the mirror, he says that he sees someone who has often moved too slowly when change was needed. The ad executive's lesson for mobile marketers? Seize the day and think bigger. "With mobile, you get not only into the pocket of a consumer, you can get into one's heart," he says.

4. Impulsive. Watching, tracking, and responding to consumer trends--these are tools of the patient, humble, and successful marketer.

If your brand is struggling, perhaps those are tools you are not using enough. Sean Lyons, global chief digital officer at the Havas agency, chides marketers who go to such conferences as South by Southwest seeking to determine which products and services will matter. The better approach? Don’t try to predict. Rather, discover and monitor. Consumers are going to decide what matters, and you need to be ready to rapidly respond as they do.

5. Inattentive. Every interaction--or inaction--can teach you something, if you're paying attention.

Google's Jason Spero calls consumer actions on mobile devices "signals," rich with information that can tell marketers a great deal if they are on the lookout for them. Spero: "We have all the signals we need to deliver a great user experience. I see more marketers that need persuading that they should be curious about those signals than I see marketers who are overusing those signals to the point of abuse or annoyance."

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Conversely, successful business leaders like Spero offered advice on the kind of relationship-building mobile marketing that is driving their success:

1. Be Pragmatic. Mobile has changed everything about marketing--and it's changed nothing.

We still need to sell stuff. It's merely the how that is different. Identify the business results you want and design your efforts to those ends. It's easy to be distracted by the pixie dust and possibilities in the digital arena. Filter the possible through the lens of what's wise.

2. Knock Gently. Mobile users are a lot more open to interactions with brands than many marketers believe--but the efforts need to be respectful.

Just because customers invite you into their homes doesn't mean you get to put your feet on the furniture, or stay all night. This means no 3 a.m. text messages for a dollar off a burger. And no push notifications every three minutes while someone is shopping. Less is more.

3. Simplify Life. Mobile is for action.

A theme that emerged often in conversation with mobile's best thinkers: Mobile should drive action. To do that, eliminate the unwanted. Beyond his or her mom, name one person who wants to read the bio of a company's CFO on a mobile Web site. List store hours, provide directions to your location, make purchases easy--whatever action your customer needs to take. Forget the rest.

4. Prize Relationship. Just as you would with a spouse or other loved one, work daily to make the interaction even richer.

Businesses have extensive information available about many of their customers. For instance, purchase data that shows what generated a response from a mobile ad or offer can give a look into the desires of a wireless user. Wise mobile marketers interpret these signals and get even more personal with tailored outreach to individual customers that proves the brand’s value.

5. Get Better. It's called mobile, right? So keep moving.

Your efforts to reach mobile users should always be evolving. You may feel you are performing well today, but you should constantly be seeking new products or technologies that enhance the mobile experience. Maybe it's a better way to tell a traveler that his or her gate has changed. Or an easier way for someone to find and save a mobile coupon. We all need to be better tomorrow than we are today. And it’s what mobile users expect and demand.

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The global mobile advertising market will hit two significant milestones in 2016: It will surpass $100 billion in spending (a nearly 430 percent increase from 2013), and it will account for more than 50 percent of all digital ad expenditure for the first time.

The stakes are high. And only the courageous will break through. To be among them, harness the power that's owned by those who are winning.