Social Bookmarking
Social bookmarking is in some ways similar to the concept of article submissions. The idea being that by bookmarking a website or encouraging the bookmarking of a site, it will help to get it noticed by the search engines. There are many ways to go about book marking a site. However, this can be a long and sometimes tedious process requiring many man-hours.
Some software systems claim they will do this automatically. But again, these systems can easily be seen and picked up by the search engines and are often viewed as unnatural. This can have long lasting negative effects on a websites ability to rank highly in the search engines.