I am a web developer who works with teams that build and market web sites, so I always have a few sites at hand which I am optimizing for the search engines, or just looking to drive traffic towards. And always we face the need, the absolute need for content. Always we start with this need: where will we get the content that the traffic will read?
Web editors, webmasters and generally every one that owns a web site needs content. Without content, your traffic is guaranteed to dry up. Take it to the bank, "no new content, your traffic will dry up." I have seen it happen countless times; we reach a few thousand hits a day, then our webmaster puts his/her feet up, quits creating new content, and few months later s/he screams "where did they all go?"
There are different forms of content. There is text content, there are downloadables, graphics and software downloads, online applications that do fun stuff (like give you search results), and more. Most webmasters simply stick with text because of bandwidth considerations, At the danger of sounding melodramatic, webmasters are pretty desperate for content.
The Other Need
Webmasters need revenue. What's the point of paying an SEOs exorbitant fees and then not getting enough money from the site to cover bandwidth costs? Everybody wants to make a little extra green to justify all that time spent in front of the computer screen. So content and revenue are the two primary needs webmasters have. Search rankings are just a way to get traffic (but before traffic must be content).
You need rankings; if you didn't you would not be here. You want high rankings on the SERPs. If you could get them without doing anything you probably would go for it, but that would be bad for everybody.
To get rankings the search engines ask for two things: links and content, in that order. Hopefully you have content, but even after content you need links, and sometimes you may not get links as rapidly as you would like. Links are delicate and sensitive things; they flee from ardent pursuers and come towards gentle "link baiters." As an individual you want to create the ultimate link bait, and get free one way links from a large number of sites with varying page rank. And how will you do it?