Andrew Badr points out, very rightly, that:
When you're choosing between opportunities to pursue, and there is any uncertainty in their outcomes, be sure to consider how long each possible outcome would take. Opportunities that would fail fast are more likely to be worth doing.
...for some reason, many people would tend to calculate the value of each opportunity over a falsely unified four-year time frame. This totally misses the additional value that comes from failing fast, which can lead to the wrong decision.
I would add that startup development techniques (like Hypothesis Driven Development) which help you fail faster are critical to achieving this. You can spend 4 years stagnating on a startup, just as easily as you can do in a corporation.