From years of troubleshooting websites for companies, I have consistently run up against the same problems.
The size of the company, or the website for that matter, has very little to do with these problems, however I usually find that larger companies have these problems at unusually higher rates than smaller companies.
Each of these problems can kill your internet marketing campaign in the search engines. They have critical importance in allowing the search engines to properly download your website to their servers and then analyze all of the information in your webpage’s code. Having your website downloaded correctly to the search engines is the first step in organic search marketing, and these issues are at the foundation of the organic strategy.