It is not unusual for even million dollar websites to have some of these mistakes
Slow website: your website needs to load in 2 seconds or less
Not Mobile Optimized: 60% or more web visitors use mobile
Ineffective Keyword Research:
may mean low traffic, low rankings, Google penalties even
Poor content: clients care about benefits, not features
To view the entire list, click this link (from Website Magazine):
Roy is the President of Horizon Web Marketing.