Under-Using Your Website - Optimizing your website involves every aspect of your site. Most people think that the only important part is the content. Optimizing content is only one piece of the pie. When you concentrate on content and not on leveraging all areas of your site, you are robbing your own pockets.
You will get visitors if your content is on point, but the search engines can rank you even higher if you used keywords in other places. Articles have titles, pages have headlines and pictures have captions. Learn to use them all to your advantage.
Keyword Overload - Search engine bots are smarter than most people give them credit for. Using keywords too much will cause them to just skip over your content and thus give you a lower ranking for those keywords. It seems like you could use as many as you wanted in an article and that would make you more visible but it's not true.
Search engines recognize when people are cheating by overstuffing their articles with keywords. Content that is well written will stay within the allowable keyword density. And, those keywords will show up naturally throughout the article so it doesn't sound like it was thrown together just for the keywords.
Keyword Density - You can have too few keywords as well as too many. Some people write their content without even thinking about keywords. You might have a strong article that talks about cutting edge information but without something to help the search engines look upon you favorably; no one will ever read it. Using the word once or twice in an article is not going to cut it.
No Variety - For better optimization, a website doesn't use just one keyword. If you started with the word "chocolate", your entire website wouldn't be based on it. People use a variety of similar words alone or in combination to find what they are looking for with search engines. If you make and sell chocolate fudge, there are better words to use: fudge, Candace's fudge, how to make fudge, etc. it's like throwing all your eggs in one basket if you don't diversify your keywords.
Reciprocal Links - While it is true that backlinks can increase your search engine ranking, all links are not equal. And search engines like organic links better than simply offering reciprocal link sharing. You want others to link to you because they like your product and what your website presents to others. Using quality content on your site, in article directories and on social bookmarking sites can increase your quality inbound links for higher ranking.
Start out on solid footing with SEO. Learn how to avoid common mistakes that first-timers make.