As an entrepreneur, the real challenge is to change people’s behavior.

In most cases, people already have a solution to the problem you’re trying to solve and now you've come along, claiming that you've got something better. Many founders believe it’s a no-brainer to improve on existing solutions and will publicly and purposefully position themselves against incumbents. Just think of all the startups claiming they can kill off email once and for all. 

Let me share a personal example: todo lists.

There are a ton of todo list apps out there. We’ve seen some beautiful examples; they’re sexy, simple and mobile-focused. A good example is Clear, which I thought looked really nice but later deleted off my phone.

So how do I manage todos? With Google Calendar and email. Yup, I’m old school, but these tools work. When I want to get things done on a specific day, I’ll add a 30-minute todo item very early in the morning, usually starting around 4 a.m. or so.

On some days I’ll have todos scheduled from 4 a.m. to 9 a.m., and then a bunch of todos that I want to accomplish at night. Putting todos in the calendar doesn’t mean I'll start working at 4 a.m., nor does it mean I'll do these things in order. But Google sends me a reminder in the morning, and those reminders sit in my inbox, reminding me what I need to do, since I, like many of you, live by my email.

If I decide I need to schedule some time for a specific todo, I'll just move the calendar item to the appropriate time, then get another reminder. If I don’t get something done, I'll move the todo to the next day (or some day in the future). If I find myself doing that a few times, it will become pretty clear the todo isn’t important.

I like this forced behavior of having to move todos and clear my inbox, because it keeps the todos front and center. My calendar and email are open in my browser all the time, so it’s hard to ignore those items.

I’ve tried a lot of todo systems, but none of them ever stuck. And that's why most products don’t hook people: they don’t provide enough value or are missing the thing that solves problems more effectively than the alternatives.

Every startup claims to have a unique differentiator, but the question is whether theirs matters.

A good example is the move towards simplifying user experiences. A lot of software is bloated and overly complex, so simplification (at a high level) is a good thing, especially on mobile.

But simplification isn’t always a powerful differentiator. Too many startups cling to simplification as the answer, but they need to consider two things: First, you need to validate that users genuinely have a hard time using the alternatives and actually want something simpler; and second, you have to be careful about stripping so much you’ve eliminated what's necessary.

Startups attack tools like email or calendars without really understanding people’s problems. Focusing on something simple might work, but there’s no guarantee it will be enough. Focusing on a more appealing design might attract some early adopters, but is that really a significant enough differentiator to change people’s behavior?

Social isn’t a guaranteed win, either. A lot of startups try to take a single person experience like todos and make it social or collaborative. They look at incumbents or older technology, most of which was built for a single person to use, and assume that if they add collaboration or social into the experience, then it will go viral and thus be more valuable. That might be true, but I wouldn’t lead with social as a unique differentiator unless you really understand that the lack of social/collaboration in an application is the core problem.

Leading with social/collaboration can also make it harder to get early adoption. Start by focusing on the single user experience and make sure that each person gets significant value independent of everyone else. If you can figure that out, you can layer social on top of that core experience to drive virality and further entrenchment into an organization or user group.

Of course, if you’re building a marketplace or social application, you’ve got to focus on the social experience out-of-the-box, but remember that even in these cases, each person uses the product on his or her own, so that experience has to be the driving factor to change his or her behavior.

It’s also important to understand whose behavior you’re trying to change. Do you have an actual market or are you boiling the ocean and going after “everyone”? Your solution might have a unique differentiator that matters--but only to a particular group of people. In that case you can point your product at a different market versus trying to “fix” the product. But finding that market is key.

Nir Eyal and Ryan Hoover recently published a book: Hooked: How to Build Habit-Forming Products, which is all about building products that change people's behavior (in your favor). I’m waiting for the print copy to arrive, but I know it’ll be well worth it. Here are three ways to focus on changing people’s behavior:

1. Find a painful enough problem

First, try really hard to ignore your biases, although you can use them to form hypotheses around the problems worth solving. Then get out there and interview users/customers/prospects and validate whether or not you’ve identified a painful problem. You need to dig deep. Pick away at obvious, macro problems until you get at the heart of the pain.

2. Test the solution

You’re going to build an MVP and put it into people’s hands. What you’re looking for is whether or not your MVP starts to break into people’s daily routines. Inside of the MVP you should have a unique differentiator that you believe--and have validated, at least to some degree--really matters, and you’ve got to figure out if that’s the case. Feedback like, “This is easy to use,” is nice, but might not be enough. Engagement is key, even if you haven’t perfected the habit-forming aspects of the product yet.

3. Build habit-forming functionality

The MVP should demonstrate an inkling towards changing people’s behavior. That is, you need some core functionality in there that’s addictive--and useful. As you’re collecting feedback on the MVP and broadening your user base, you want to really hone in on usage, engagement, and retention. You want to look at each feature in your app and understand if it’s moving people towards the behavior change that you want.

Really, this is the Lean Startup process. But I think a lot of folks use Lean Startup at too high a level and don’t dig into the nitty gritty of what they have to do. Ultimately, it’s all about changing people’s behaviors. You need to have that mindset in place from Day One, to make sure that you’re focused on how to do that successfully.

This post originally appeared on and has been reprinted with the author's permission.