The topmost factor that can lead to a startup death is lack of idea scalability. It happens when you move on without doing enough research before building up your business idea. Next slip-up that failed startups have committed is the lack of focus. This is the common mistake made by all the growing websites that shut down sooner or later. As a startup business you need to understand, It doesn’t matter how large or small your business is, during initial phase, progress will come at a snail’s pace.

I will recommend you guys to read this awesome post written on startups: http://www.fatbit.com/fab/biggest-online-startup-failures-read-learn/