The search here...for lack of better words....sucks.
(in large part due to them having the lowest bidder make the site and forums)

It's better to search for things via one's search engine of choice like so:

term(s) site:gog.com

(like if you want to search for doom eternal posts in the forums, for example, you'd search for doom eternal site:gog.com)

Hope the above helps :)


edit: you can also search user names as terms as well using the above method....if you want to find posts by certain users.