Ah yes. Link building.
We can name 3 major services on the Internet who manage the link building for 1000s of companies. One of these companies is infamous for posting links to clients on irrelevant websites, forums, directories and other locations for the sole purpose of creating backlinks to your website. If these websites are unrelated to your business or if they have nonsense forums that are just a collection of spammers to drive traffic then these are not contextual links.