My view is it's fine for people to post threads for/to their own content as long as: 1) most of the time it's gaming related, and 2) they're taking part in the community in other ways too (the most obvious example being making posts in other threads) and not just using the site as an outlet to spam advertise their own stuff. This is the rule most subreddits adopt and I think it's a good one.
This is my view as well. So long as it doesn't become a personal advertisement and it is relevant to site interests then I'm all for it. If ever in doubt, ask one of the mods who have posted in here or a Site Admin like Machina.