WHERE YOU ARE
Assuming your site is broken down into sections, as most are, and possibly into subsections, let your visitors know exactly where they are within your site. Many sites implement this idea as it will bring many visitors back to one of your main pages once they're done with the page they're on. A common way to do this is put a nested array of hyperlinks atop the page. For example, on a page titled "manuals" you might have an array something like this:-
Home > Books > Training > Manuals
This way the visitor can easily get back to or visit any of the other preceeding pages in the array.

RELATED CONTENT LIST
At the end of your content you could provide links to related resources. By offering content similar to the content your visitor just read, they'll be most likely to continue within your site by reading some of this related content. This can even be set up as a link trade with another webmaster, to guide users to related affiliate programmes. Any way you do it, your visitors can only thank you for helping them find what they need! A text link or a link and short description would be most effective.

LINKS WITHIN CONTENT
Link to other pages of your site from within your content. If you mention a topic covered on another page of your site, mentioning it with a link within the content your visitor is reading can easily compel them to visit that other page in addition to the one they're reading. This can also be useful for promoting affiliate programmes related to your content.

ADVERTISE YOURSELF
There's no reason not to promote the site your visitor is already on (or another of your websites if you have more). Creating ads running in specific sections of your site or on specific pages can also lead visitors back to other pages within your site. If you don't have many ads to circulate, this is another good way to keep visitors within your site. See also our page on promoting your website

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