There are many mistakes which people can make that result in killing your website. These are often simple and avoidable mistakes which can 
cripple your chances of optimizing your site. The first mistake is coding. Coding can hurt your SEO if you choose to use difficult coding such as Javascript. Simpler code can offer the same results with less spider issues.
The second mistake often made is the choice of keywords. When people decide upon the keyword phrases they should pick a select few which will then be integrated throughout their site. By focusing on a small group of important keywords you can increase your SEO. If you try to incorporate every keyword which relates to your niche then you will waste all of your time trying to incorporate each word in all of your web content and will lose out on many search engine results.
The third mistake people make is having long and confusing URL’s which cannot be navigated with ease. The best URL will have relevant keywords and only use dynamic characters or a few slashes. The pages and names should be in line with your specific content so that the spiders and visitors can appreciate it.
The fourth mistake made is thinking that title tags do not matter. You cannot get away with only using a single title tag throughout your website. You need to create a unique title tag for each page which will explain what the page is about. These title tags will show up in all search engine results and as such can better convince visitors to click on your website.
The fifth mistake is not watching out for splash pages. It is important not to leave your home page bare. You need to keep it focused. If you do use a splash page you want to ensure that the content contained therein is relevant and has lots of navigation in it so that the search engines will go through your entire site.
The sixth mistake is thinking that all of the search engines are the same. Each search engine has a unique plan and your business might rank better with one search engine than another. The top search engines are Yahoo, MSN, and Google because they can attract local attention to your niche through vertical and visual search engines. The seventh mistake made which can kill your company’s SEO is just trading backlinks instead of getting good backlinks. It is important that you get links from related sites which are of good quality. If you trade backlinks with other webmasters you might not help your SEO rank as much as you think, especially if they are unrelated to your niche.
The eighth mistake is not balancing graphics and text. It can be very detrimental to have underutilized graphics or excess graphics. With a lot of flash or too many images your rank will go down instead of increasing. You need to always have text to back up the images.
The ninth biggest mistake which can adversely affect your SEO is not delivering your promises. Your site should offer everything that you say it offers so that visitors find what they want and expect on your site.
The tenth and final mistake made is thinking that only SEO matters and not paying attention to the other facets of your balanced marketing plan.
