The reason’s I believe that so many people who venture into internet marketing fail is because a lot of newbie's will have high expectations of earning a lot of money fast from the internet. They have the mindset of believing that success will come easy. This will usually not happen, and they will end up getting frustrated and quit.
Fail to take action. Surprisingly many people who are starting out in Internet Marketing have the mindset that they don't need to take massive action or work hard in order to succeed.
They may also believe it is too expensive; you will not have to break the bank in order to set up your own internet business. There is loads of free info on the net that can help you get started.