SEO Research: SEO keywords, SEO terms & SEO ....

Keyword Density

Keyword density refers to the ratio (percentage) of keywords contained within the total number of indexable words within a web page. The preferred keyword density ratio varies from search engine to search engine. In general, I recommend using a keyword density ratio in the range of 2-8%.

You may like to use this real-time keyword analysis tool to help you optimize a web page's keyword density ratio.

Keyword Frequency

Keyword frequency refers to the number of times a keyword or keyword phrase appears within a web page. The theory is that the more times a keyword or keyword phrase appears within a web page, the more relevance a search engine is likely to give the page for a search with those keywords.

In general, I recommend that you ensure that the most important keyword or keyword phrase is the most frequently use keywords in a web page. But be careful not to abuse the system by repeating the same keyword or keyword phrases over and over again.

Keyword Prominence

Keyword prominence refers to how prominent keywords are within a web page. The general recommendation is to place important keywords at, or near, the start of a web page, sentence, TITLE or META tag.

Keyword Proximity

Keyword proximity refers to the closeness between two or more keywords. In general, the closer the keywords are, the better.

For example:

    How Keyword Density Affects Search Engine Rankings

    How Keyword Density Affects Rankings In Search Engine

Using the example above, if someone searched for "search engine rankings," a web page containing the first sentence is more likely to rank higher than the second. The reason is because the keywords are placed closer together. This is assuming that everything else is equal, of course.

source :  http://www.mikes-marketing-tools.com/marketing-tips/keyword-densities.html

Keyword proximity and the keyword density within your Website can make or break your search engine optimization efforts.

If you target a keyword phrase, you will often find that the difference between your keyword search and the same search using "stop words" (e.g. in, and, we, and of course, your company name or Website address) are vastly different. You should avoid "filler words" or "stop words" between important keywords. This is because if you can top the search engine results for non-broken phrases, you will be more likely to top a search engine for the broken search phrase as well. This is to say, far more likely than the reverse. 

Also, the logical search and the keyword phrase reversed (e.g. widgets Kansas vs. Kansas widgets) return much different results. Therefore, proximity should be used wisely.

An effective use of keyword proximity is to use your prominent keyword or keyword phrase in both forward and reverse proximity.

If I determined that the target keyword phrase is "accelerated dial-up", I will want to use keyword proximity such as the following:      Title: Accelerated Dial-Up
                           Description: Accelerated dial-up: Surf faster with dial-up accelerated to 5x the speed.

 source : http://www.yournew.com/keyword_proximity.cfm 

The services listed below generally sell paid listings on a cost-per-click or CPC basis. They are also sometimes called PPC or pay per click search engines. Advertisers pay for every click the search engine sends them, and those who pay the most generally get listed higher.

Say , google is putting our link on its adwords , we have to pay for eack link click by an user .
Benefit to Google : we r paying at each click
Benefit to us : User visiting our site .

People can simply click your ad to make a purchase or learn more about you. Now you can advertise to people searching on Google. Even if you already appear in Google's search results, AdWords can help you target new audiences on Google and our advertising network.
You can edit your ads and adjust your budget until you get the results you want. There's no minimum spending requirement--the amount you pay for AdWords is completely up to you. Charged only if someone clicks your ad, not when your ad is displayed.

Is CPM better than PPC ?
I was thinking about google's cost per thounsand impression adword plan. It helps to build image for a company. When a particular ad shows infront of you thousands of time then you probably click on it once and may purchase some thing from the site. I used it for my couple of sites and got huge visitors and clicks. For me CPM is better than CPC ad.

source : adwords.google.com