Seo Content Writing on web pages is actually a part of web design and development. But very few design firms actually have a competent content writer.
The contents should impress the visitor and there should be some ad elements to your content like what copywriters provide to Ad agencies.
Visitors do not read full content so use tag lines to tell the visitor what is the key topic of the web pages. In all pages the title and meta tags should be unique else your site will not perform well. Highlight important words using CSS and define terms using h1, h2 and h3 tags on the page. These tags should strictly be topic related and the hierarchy should be set by you keeping the relevant importance of your web page and the search term targeted.
These are important elements for search engine optimization for website promotion and makes the web page useful to the web visitors, best taken care during the web designing process. The web page design should be easy to navigate from one important link to another and relevant content finding should be made easy by proving well placed internal links which do not open in a new window.
What ever the number of pages your website contains, make sure that each has something new to offer. The Url and Title should define the topic well. If the URL does not contain topic related keywords than rename the resource URLs and use redirect to direct the old url to new url if substantial back links point to it.
The existence of a website page is to provide something useful to the site visitors. This should always be kept in mind. Even if the page is meant for advertisement the ratio of content to ads should be in the favor of the content. This is in order to provide useful.
Keep the content in well defined blocks and set the pattern for all web pages as the same. You should provide additional information about the product and service Vis a Vis its technology, market position etc.
You can add one or two out going links to site that provide useful additional information on terms which are not elaborated on your web pages. This if done correctly will increase the value and uniqueness of website content.
The addition of key words should be done naturally along with the inclusion of semantic terms which explains your topic or concept better. The key word density is not so important now a days but if you can increase the keyword density naturally to five to six percent it will help with many search engines.