Keywords are not only important with its(keyword) density, but the quality of these keywords is also concerned. If the certain keywords density in your site is almost same as the others' one, or even you are not that optimum than theirs, but if you have the important keywords in your link, then this will definitely boost your ranking incredibly. That's not only links, but also some parts of the site, which I will discuss about it later on.

Keywords in URL

Comparisons in URL

As I stated, keywords in your URL are very vitally important, as they will give you a great advantage to boost your ranking (compare to those who don't have). i.e. Let’s say we use 'dogs' as the keyword. If you search dogs, thousands of sites are coming out. But, if you are managing site that involved this niche, how will you get on top of the others? That's the question. There are thousands of ways to boost your ranking, but we talk about using link to optimize your keyword first. If you have a link entitled with 'dogs-care.net' will be better as compared to 'animal-care.net'. For example, if you have a ‘dog-care.net’ while the other don’t have ‘dog’ in their url( search query for dog). To a certain extent, you might able to be in top-page while the others are still struggling in getting the 100th ranking. That's how important it is.

Directories of links

What's about directory of links? This example might able to give you a clearer explanation. i.e. http://world-avenue.com/about.htm. The highlighted words are the file name of the directory of the links. Besides the main page url, which is http://world-avenue.com, the directories of the main url do help in SEO.

i.e. If you're given http://dog-care.net/dog.htm, http://dog-care.net/animal.htm and http://animal-care.net/animal.htm, then the first one will be rather better than the second and the third one. Definitely, third one will be the worst among them. Well, I guess you should understand now, if you are optimizing the certain keyword, try to emphasize the keyword in URL before you creating it.

Length of the links

Well, the number of words in your main url like http://dogs-care.net should be wisely controlled  Do not be over-stuffed word phrase into the link, which may usually cause reader unable to remember your link well. So, it's best to be 2~4 words, make it short and clear!