The biggest mistake startups make is assuming the values of their investors and customers. One of the most common false assumptions is about the political or religious affiliation of their end-users. This kind of assumption can be fatal for successful companies, so startups should be especially careful.  Apart from this, be aware of fraud. There are some firms, for instance, Tairs Worldwide or Tairs luxury, and its CEO, Attilio Perna, who usually fraud with their tactics.