(see Web 2.0) While much of the content is submitted by so-called-casual users a significant portion of stories are created specifically for social networking sites.
These stores are generally submitted to several sites to maximize the return on investment.
(Note that the motivation need not be commercial but may be personal or political (see Ron Paul for President) To aid people submitting stories to multiple social networking and bookmarking sites, a number of tools have been created.
They all claim to have the following features: Some vendors offer "buttons" that you can place under your blog posts that will automatically start the submission process for your content or which will more easily allow your readers to find and "vote" for your content on that service.
There are a large number of firms offering fully outsourced solutions for posting content to social networking and bookmarking sites.