Everyone knows that a bookmark is a piece of paper that marks a page so you can find it easily again. Most people know that a computer bookmark is a link on your computer that marks a web page so you can find it easily again.

A social bookmark is a link that marks a web page so you can find it easily again, but also so you can share it with others, usually by posting it to one of several dozen social-bookmarking websites.

Social bookmarking is all the rage these days, with websites like Del.icio.us and Digg commanding a presence among the top traffic generators on the Internet. People like to bookmark their "finds" and they like to show off their "fiends" to others. Hence bookmarking, hence social bookmarking.

Webmasters hoping to capture the attention of today's Internet user should heed the signs and recognize the phenomenal opportunity presented by social bookmarking. In a follow-up article, I will explain the "how-to"s, but here are five ways a website can benefit from social bookmarking.

REPEAT VISITORS: Considering that many people do not buy/register/contact/take action on their first visit to your website, repeat visitors are a necessity (not to mention laser-targeted prospects!) You can get more repeat visitors to your website if they can find your website again. That means getting them to bookmark your website, either on their computer or on the social bookmarking site of their choice. The more bookmarking options you offer, the more visitors are likely to return. The easier you make it for them to bookmark your site, the more of them will. However, you really must have quality content, or nobody will want to bookmark your page.

VIRAL BOOKMARKING: When somebody bookmarks your website on their own computer, they share it with, well, themselves. It's a private thing. But when they bookmark a web page on a social bookmarking, it's more "social". Other people will see it. Other people might share it. Other people might even bookmark it. Websites like Del.icio.us, Ma.gnolia and SpicyPage are ideal for this. In fact, many of the biggest users of a social bookmark website are often users of several. However, you really must have quality content, or nobody will care that somebody else has bookmarked your page.

VIRAL LINKING: When somebody sees your link at a social bookmarking website, they might bookmark it...or they might add it to their own blog or portal or fan site. Suddenly one person's bookmark becomes several links to your website, presumably from reasonably well-targeted sources of traffic. However, you really must have quality content, or nobody will want to blog somebody else's bookmark.

SEO-FRIENDLY LINKS: Many of the social bookmarking websites offer no direct SEO value. The links might feature the NoFollow attribute. Or the mea robots tag might be set to NoFollow. Or your bookmarks might not show on unique URLs. Os the links might use a redirect script that search engine spiders don't follow. But there are some social bookmarking websites that offer SEO-friendly links.

SEO-FRIENDLY LINKS ELSEWHERE: Even if a link from a social bookmarking website is not SEO-friendly, don't underestimate its SEO potential. There is a whole industry growing just to game Digg and Del.icio.us, knowing that if a website's bookmark can stick on the home page for an hour or two, it will mean dozens or even hundreds of inbound links from reasonably relevant blogs and portals and fan sites. And this is natural linking, the kind that search engines love! However, you really must have quality content, or whose going to post a link to your website just because they found it bookmarked?