Benefits of having a high PR
Important, high-quality sites receive a higher PageRank, which Google remembers each time it conducts a search.
Google combines PageRank with sophisticated text-matching techniques to find pages that are both important and relevant to your search
How does page rank affect your listing in SERPs (Search Engine Result Pages)?
- It still does affect SERP but not as much as before, today it is not recommended to exchange links to increase their PR Google sees that as trying to "game" their search engine. It is generally accepted that exchanging/buying links purely for PR is a waste of time (and, in fact, can have detrimental effects).
- If local rank is a factor in Google's ranking algo, then PR is still very much important. It just may depend on the sources of a page's page rank.
- Google still using PR as part of their Algorithm for SERP (“I don’t see why they'd stop using PR as a part of their algo when it’s what the whole search engine was based on in the first place”)
- PR also influence how frequently googlebot spiders your site
- The more competitive the word, the higher the PR needs to be
What detrimental effects will I face for buying PR?
Sites with higher PR often make money by selling links on their high PR pages. If Google is aware that they are selling PR rather than just selling ad space (don't ask me how Google can tell the difference or if, indeed, they can) Google may penalise both the seller and buyer. This can take the form of lowering where you appear in the results but may not necessarily result in a downgrade of the PR you see in the toolbar.
“We have done extensive research to find out if pagerank influences site rankings. In short, it doesn't. We haven't found any strong corellation here. If you are interested, I can share the details here.” - Web CEO (an SEO software company).