I’ve noticed this another night too and the mods cleaned it up. But why is the nVidia forum the place to spam like this? How does this keep happening?
It seems pretty straightforward how it happens: Someone creates a throwaway account and copies a spam template into as many new posts as they can before their account gets banned.
As for why? It’s hard to say. NVIDIA’s forums probably have pretty good ranking on Google, so maybe getting spam links onto it helps improve their appearance in search engines?
Stopping this kind of spam is a tough problem, since pretty much any automated technique to block it can be avoided if the spammers are willing to adapt.