Chiming in to note that the most successful ‘marketing’ I’ve done by far (for my unpublished HG WIP, mind) has been through Tumblr; posting and sharing regularly on there with a dedicated account for my WIP has brought around 1,500 readers who stumbled upon the game nebulously, the majority of whom (so far as I’m aware) weren’t already aware of the game through the COG forums.
Also tagging in @Eric_Moser’s thread on author marketing from last year, this other old thread about game promotion and ROI, this ChoiceScript wiki article on Choice Game Marketing, and this list of author social media accounts in case anyone wants to add their own or take a peek at what others are doing. Oh, and this thread about social media platforms that are useful for talking about Hosted Games!
These aren’t necessarily specific leads, so I’m also going to throw out sub-q magazine, which I’ve heard about from @HarrisPS. They’re a publication for interactive fiction and seem to do interviews and columns and news about IF, so maybe contacting them would be worth a shot!