kingcharles and others have touched on many great topics.
An official page on Facebook is a good place to start. Most of us have friends with similar interests and the low/no cost of Facebook is a good venue for "word of mouth"
Facebook is good for virtual word of mouth, but blogs are the gateway to the masses. (a few ideas that I have here, I will post separately)
The complexity of the game can be daunting for newcomers. There needs to be more "plug & play" options and quickstarts that come with the game. The modding community is great, but newcomers don't often consider the mods when buying a brand new game.
With that being said, OOTP's depth is a great strength and that is a selling point.
If targeting the Fantasy crowd, the MLB rosters need to be solid and a focal point of the advertising.
There should also be relentless focus that any historical season can be played without the additional costs of season disks. There is still a market to gain crossover interest from SOM, Pursue the Pennant, APBA, etc and the ability to play historical seasons without an additional cost is a huge plus.
Banner ads can be effective and mlbtradrumors is a great place to start. Perhaps some type of banner exchange can be agreed to with some smaller sites that fit the same "geek" (no slight taken) target group. Most web sites that I frequent daily, I learned about from other users on the OOTP boards.
Hardball Times
Fangraphs (implement their
Win Probability Graph in addition to box scores and game logs using their logo within the game similar to Baseball Prospectus in exchange for some banner space) I would love it if this was a widget on the game broadcash screen.
Uniwatch - In addition to possible ad space, a user could do a write up of uni/logo customization availble in the game.
Baseball Musings and Ballhype would also be good locations.
Any banners should direct the potential customer to a well designed and informative home page. (the OOTP X page is a huge improvement over past incarnations)
Most OOTP users now go straight to the boards and never visit the main page. The amount of unfiltered content (which is a good thing) on the boards could be a detraction for a potential purchaser.
While the fictional aspect and customization are part of what sets OOTP apart from the competition, most new users are looking for a simulator of MLB. My guess is most OOTP users were looking for a real roster or historical simulator and later came to love the fictional aspect of the simulation.
Most OOTP users now go straight to the boards and never visit the main page. The amount of unfiltered content (which is a good thing) on the boards could be a detraction for a potential purchaser.
Most importantly the release (and demo) of a new version must align with the start of the MLB season.