From the last few I have seen. The point of their post is so they can post a link on the board. If you look in their signature there will be (was) a link for some company. The link is all they want, this gives the link more credibility with the search engines (Google) and therefor their site is ranked higher in returns. If a form of black hat (bad)
SEO
So if I own a website, I want to go to every board I can find that is indexed by search engines and post links on their sites to mine.
These posters have a interest in whatever company's website they had in their signature. Sometimes they are unscrupulous employees but more of often they are simply hired to spam any online forum with links. They get a few cents per link posted.
sjc
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