Paid placement guarantees a site owner a special place for his site, paid inclusion is a lot simpler. It involves paying a fee to the search engine just to be included somewhere in the site’s regular SERP listings, or be considered for a listing. Evidently, lesser perks that paid placement! Search engines usually always emphasize that paid inclusion payments do not provide a boost in the rankings of the site on SERPs.
When would site owners need to pay to have their sites merely listed?
For one, someone with a brand new site might want to submit their page for inclusion so that the page gets listed faster (say within a couple of days), in comparison to natural listing, which might take up to a couple of months (the crawler does take time to find over the net!). Once again, inclusion does not guarantee good placement. Whether the site gets a good rank on the SERPs depends on the site’s page ranking technique.
Another example. Someone might have a page that is constantly updated, and one page might show very different content as compared to its earlier content. This is a common scenario. Paid inclusion would allow this site to be updated on the SERPs in a couple of days, rather than a 2 month wait for the crawler to find the updated site.
A final scenario. Crawler based engines do not manage to find all the pages of a website, particularly when some pages are buried deep within the hierarchy of pages. With paid inclusion, a website owner can make sure that all the pages are included in the non sponsored results pages.