Why most web projects fail?

Why most web projects "fail"? My personal opinion and belief is due to the sale. If no sale, no money and everything is in place. You have a beautiful design, najvalidniji code, the best idea najkorisniju thing, top SEO, top developers, but if not sales all costs. On the other hand you can have an average design, nevalidan in an ordinary web, bad SEO and a bad programmer, but if you have sold a successful website. How many times have you heard and saw that people are selling something before it existed? Likely to read every day in newspapers.

SEO is not a component that will make a successful website or not. It is perhaps only one channel or more factors on that route. What will your SEO without selling? Focus on sales.