Alexa von Tobel, founder and CEO of personal finance website LearnVest, set out on a mission in 2008: She wanted to create an inexpensive platform that would connect the 99 percent of Americans who do not have access to sound financial advice with trustworthy money managers.

But von Tobel says success takes more than just a genuine, earnest attempt to change the world for the better. In addition to several lessons for building a startup, she has tips to help make sure your company makes it through the growing pains of its first three years.

Read the most important lessons for young startups von Tobel learned during LearnVest's earliest days below, and check out a video of her speaking during the Inc. GrowCo event last April.--Will Yakowicz

Listen to your customers obsessively.

"Every single night, right before I go to bed, I spend 30 minutes reading feedback emails from my users. Even now, as we get thousands per day, I quickly scour them so I can get a sense of what's happening," von Tobel says. "Your users, they love you and they showed up. But when it's a matter of what they hate and love, do more of what they love and less than what they hate. It's not rocket science, but if you don't have customers, you don't have a business."

Don't be afraid to adapt.

"Every three months, have a summit with yourself where you can ask, 'What's changed? What are the facts? What did we used to think was real and what's not real anymore? What's happening in the industry and what's changing?' You have to change and be on the cutting edge," von Tobel says. 

Identify your company's metrics.

"You need to identity the five most important metrics that matter most to your business and look at them every single day. You can think a lot about your business, but it doesn't matter. What does matter is what's happening all day long: Are your users growing? ... Are users logging in? How many customers are referring others?" she says. "We track these things obsessively. If these numbers go up or down, there's a reason and you need to find out."

Always be hiring.

"Look for outside passion, people who come and love your business and are passionate about your space. You may not have a position for them today, but you will later on," she says. "The difference between a good hire and a great hire is the difference between you succeeding and failing. A great hire is someone extremely smart and talented, but the X factor is they're obsessed with what you are building and they care. It feeds their soul. Everyone at LearnVest literally believes we are changing the world."