1. Many people are not getting good or complete advice. Often for example people don't understand all the concepts of Internet Marketing and having a website so they simply pay to have a website developed. Often this website may look good but it falls far short in the area of being "search engine friendly". This is typically because many businesses that deal with the web are very one track focused.
People need to get independent opinions from a knowledgeable person. Someone who doesn't have a biased agenda. Most businesses have a product or service they try to push customers toward because they make a greater profit on these items.
Many businesses that deal with the internet can be narrowly focused on their one main niche. They may do webpage design and development and for their ease they either knowingly or not don't consider other important attributes like optimizing the page for search engine placement. Some example are weblinks in java scripts. Search engines don't read these. Another example is the over use of images to display text on webpage. Search engines develop your webpages reputation based upon the words on the page. If the words are in images they can't be read by the search engines. A simple test to search for words is in your internet browser click on Edit and then click on Find and search on any suspect words.
2. People put too much emphasis on their Company name in their website title. The title should be geared toward keywords, etc. They don't take into account search engines and keywords and that starting out nobody is going to be searching on their Company Name.
3. People don't wisely choose their keywords or market. Planning here is key