Here is the list of top 10 factors that affect search engine ranking.
1. Use of Keywords in Title Tag
If I am allowed to work on only one aspect of a site, I would work on the Title Tag . Put all your keyphrases in your title tag, but also remember not to overstuff it! For best results you gotta optimize each page individually.. Lets say your first page has information about “free antivirus” then you should have key phrases like – “free antivirus, download antivirus, best antivirus” etc. Lets say your second page has information about “firewalls” include keyphrases like “free firewall, best firewall” etc.
2. Keyword Use in Body Text
Now its pretty obvious that if your web page doesn’t contain any information about Antivirus but still contains key phrases like -– “free antivirus, download antivirus, best antivirus”, it aint gonna work!! The point being, please make sure that you have the text in the webpage that you have on your title tag!! Don’t worry about the density of the key words. There is no relation between the density of the keyword and its rank on the search engine
3. Relationship of Body Text Content to Keywords
Remember, google is google because its got some serious smart guys working for it, so don’t be under the impression that fooling them is gonna be easy. Just stuffing a key phrase into a completely unrelated page wont do you much good.
4. Keyword Use in Domain Name
Some disagree with the importance of this one, though I feel it does not play a major role, why take a chance? Especially if you want to start a new site.. That said, remember that you choose to lose more than gain if you have an established site with a good pagerank! Note that there are websites that offer excellent services when it comes to web hosting
5. Keyword Use in Page URL
Again different SEOs take different sides on the importance of this one. I believe it is of some importance, but doesn’t make sense to change the urls for an existing site with a decent pagerank.
6. Keyword Use in ALT Attributes and Image Titles
I think this is extremely important. Maybe even more important than url and domain name. Experince shows that image optimization is a wonderful way to make a page appear higher on the search list to a desired query
7. Keyword Use in H1 Tag
Inspite of critics deeming tweaking with H1 tags as useless, its been proved otherwise. Head up the body text with an H1 containing the keyphrase.
8. Keyword Use in H2, H3, H… Tags
Since we have used it in H1, why not use it in H2, H3, et al..
9. Keyword Use in Bold/Strong Tags
I deem this method as moderately important. It helps Google in analysing what your page is about and what can the reader expect to find on it.
10. Keyword Use in Meta Description Tag
Definitely important. Each page should have a custom title and meta description tag. The ability of the Meta Tag to make it appear on the search list should not be underestimated.
All said and done, it should be remembered that CONTENT is the king!!