According to a study by the Startup Genome Report, most start-ups fail due to premature scaling. In simple terms, they try to grow too fast, spend money on the wrong things, hire too many people, etc.

This may have some truth but from personal experience in working for and with start-ups, there are two bigger and more fundamental reasons why most start-ups fail:

1. Their idea or vision isn’t compelling, interesting or fills a void or need.

2. Their usability of their Web sites is terrible, making it difficult, if not impossible, for time-strapped consumers to understand the service, let alone embrace it.

It’s a devastating one-two punch that leaves many start-ups doomed from the beginning, regardless of how well they scale or manage their money.

Much like it takes little time to tell whether you’re going to click with someone on a date, you can tell fairly quickly whether a start-up has any chance of success based on their idea and usability.

Let’s take a look at these two key ingredients:

The idea: At the end of the day, a great idea is going to make or break a start-up. You can layer on whatever you want such as excellent public relations and social media programs or a beautiful design but if the underlying service doesn’t meet a need, void or delight a user, the chances of it winning over enough consumers to create a business are bleak. It’s the old adage that “You can put lipstick on a pig, but it’s still a pig”.

Too many start-ups get excited about creating a feature rather than a service. What they’re offering is interesting but not interesting enough to get enough people on board. That siad, you would be surprised to see how many entrepreneurs fall so deeply in love with their idea that they forget about whether it has enough substance to be compelling to other people.

Usability: Assuming the core idea has some potential, too many start-ups doom themselves with bad messaging, navigation and design. It means that even if someone found the service to have some appeal, their ability to try it out is under-mined by confusing language, un-intuitive navigation and weak calls to action.

The truth is most Web users are lazy. They want things to be easy, user-friendly and not involve a lot of work. As a result, an online service has to be totally accessible and a snap to grasp, otherwise users will quickly move on to the next service or thing that catches their eye. Some good examples of companies that pass the “get” test with flying colours are MailChimp, Freshbooks and DropBox. In takes seconds to know what they offer, and what people should do next after visiting their sites.

From where I sit, the idea and usability set the stage for failure or success before premature scaling. Many start-ups don’t even get the chance to prematurely scale because they’ve already failed.

For entrepreneurs, it means they should test and re-test their idea. Does it resonate with people enough to seriously explore it? Does it fill a need or void? Is a service or a feature? Then, the focus has to be on making the service accessible enough so enough people will take it for a test-drive and, hopefully, become users.

For more thoughts on the Startup Genome Report, check out John Cook on GeekWire.

As well, a good read is Rob Walling’s blog post on the importance of start-ups being able to find a way to convince consumers to give you more money than what it costs to acquire them.