Ernest Garcia
Analyst · Wells Fargo
Thanks, Mike, and thanks, everyone, for joining the call. As we have in prior quarters, we put a shareholder letter out on the Investor Relations site. We put a lot of detailed information in the letter relating to both the fourth quarter and the year as a whole, so I'll spend most of my time today focusing on key milestones and trends in our business.
Let me start in the obvious place. There's admittedly some noise in our results. We missed our own guidance in unit sales in the fourth quarter. We also grew revenue 148% year-over-year, our highest growth rate ever as a public company, which begs the question, how did that combination of facts happen? The answer is that we had a great fourth quarter by any reasonable measure. We also had unexpectedly weak results from our Cyber Monday promotion that surprised us, and we failed to sufficiently factor the unexpected into our guidance. That noise was completely self-inflicted. That said, it is noise.
So what are we excited about as we head into 2018? In the shareholder letter, we included several graphs that we believe highlight the most important financial measures of the business. They include units, revenue, GPU, number of markets, number of vending machines and EBITDA margin. Examining these numbers annually is helpful because it provides a bigger perspective that makes the Carvana story very clear. Please take a moment to look over these graphs.
In addition, we include our cohort market penetration curves. We also really like the story these curves tell. Our growth continues to be significant and consistent across markets. Our most mature cohort, the 2013 cohort, reached a market penetration of 1.54% on growth of 44% in the fourth quarter year-over-year. We don't know how high our market penetration can ultimately be but even if you assume that 44% growth rate drops to 0 from here, the penetration we have already achieved in that cohort would enable us to get to a scale that is over 13x where we ended 2017 if we can get nationwide penetration to the same level.
We are just getting started. Carvana is now a 5-year-old company. In that short time, we have established ourselves as the leaders in automotive e-commerce. Our customers can buy a car in minutes on our website while getting approved for financing, pricing their trade-in and signing contracts without ever leaving their couch. They can have their car delivered as soon as the next day through our in-house logistics network, with the car arriving at their door accompanied by a Carvana customer advocate who shares their enthusiasm for the moment. This offering is powerful and difficult to replicate as it requires expertise in many areas. The numbers reflect this power and uniqueness.
All of this has been accompanied by significant GPU growth and significant operating leverage. Over the last 3 years, we've grown GPU from negative $200 per unit to over $1,500 per unit, and we have improved our EBITDA margin from negative 32% to negative 17%. We've achieved this while rapidly scaling, evidenced by a cumulative annualized growth rate of over 175% and 140% in units and markets respectively over that period. We view this as a significant accomplishment with few precedents in either the public or private markets.
Accomplishing all of this so quickly is a testament to 4 things: the size of our opportunity; the quality of product we have put in front of our customers; the scalability of our model; and most importantly, the caliber of people who have made the Carvana mission their mission. These graphs extrapolate to achieving massive scale in straightforward ways. So what stands in our way?
We believe the biggest hurdle we face is execution risk. We need to continue scaling sourcing cars for our customers, certifying them, transporting them through our logistics network and delivering them to our customers' doors and, most importantly, wowing our customers every step along the way. Each step carries risk, and we think a useful way to examine these risks is to separate them into 2 buckets: the operational bucket and the customer experience bucket.
The operational bucket is a big one. The good news is that this risk is -- mostly impacts the time it takes us to achieve any given milestone more so than the ability to ultimately hit that milestone. We're very focused on anticipating and mitigating operational risks and have an incredible team with strong leadership in each operational area, which gives us confidence in our ability to manage this risk going forward. This confidence is underscored by the fact that we opened 23 markets in 2017 and have already opened 10 more so far in 2018. We also opened our first Carvana build inspection center and opened 5 vending machines, the most in our history. That all came together with the delivery of over 44,000 cars to happy customers this year.
Second is the customer experience bucket. This reduces to a simple question: can we continue to deliver and improve upon the customer experience we pioneered at the next order of magnitude? In our opinion, this is the most important risk we face because it not only impacts the time it takes to achieve any given milestone but also dictates which milestones are ultimately achievable. This is a measure, we have fared very well on to date. We now have reviews from over 14,000 customers with an average rating of 4.7 stars. 10,000 of those reviews came in the last year alone.
Given these risks and the sheer size of the opportunity we face, our strategic plan is to be aggressive while always keeping the customer experience at the center of every decision we make. Opening markets quickly kicks off key network effects in inventory, marketing and brand, but also generates additional execution and customer experience risks that we must be mindful of. This reality puts our goals of aggressively seizing this opportunity and delivering the best customer experience available to our customers in conflict to some degree.
That conflict is resolved by the quality of our operations. As long as we continue to execute at the level that enabled us to grow revenue by 135%, grow markets from 21 to 44 and to deliver customer experiences that earned us those 14,000 4.7-star reviews, we will continue to accelerate in this exciting opportunity so our customers, team members and shareholders benefit from the positive feedback of growth inherent in our model. We know that the triple-digit growth tapped into this tremendous opportunity will not always be a straight line, but we believe we will achieve our goals as long as we keep our eyes on our mission to change the way people buy cars.
We're entering 2018 proud of our accomplishments, but not satisfied. We also believe the opportunity we have is incredibly unique, and we feel privileged to be the team tackling it. We are up to the challenge. Mark?