Have you come across marketing emails that guarantee you link placement on a PR9 (PageRank) web site? It’s highly unlikely that your link will be included on a PR9 page and in most cases they will place your link on a highly ranked web site, but your link will be placed on deeper pages inside the site that have a much lower rank or no rank at all (unranked).
This is a scam to take your money by making false promises and this type of scam has been around for a very long time. There are also other issues that can occur without your knowledge by having your link added to sites that are deemed malicious, dangerous and or have a poor reputation.
In order to properly build your Pagerank in Google, you will need to do it the old fashion way by commenting on blogs within your niche (relevant to your sites content) and sharing your web pages on social networks. There’s no guarantee that the sites you comment on have the nofollow attribute removed, but if you’re using Firefox as your browser of choice you can download the add-on NoDoFollow. This Firefox add-on simply highlights links in a page according to nofollow / dofollow status. Pink highlight for NoFollow links and Blue highlight for DoFollow links.
Be careful about what people promise as there are too many scams on the internet that could empty your pockets without delivering the service/s they guarantee.
There are some reputable marketing firms that can get your link posted on a PR9 web page, but in many cases there are time restrictions and your link is eventually removed when the time frame expires.