I would love to see them have tournaments and competitions with prizes involved. Definitely not any kind of weapons as a prize but maybe skins for weapons, unique equipment (ex. hats,tattoos, shirts ect.), Autographed Brink posters ect.
Yeah, no unique weapons, but in-game content like skins - like you said
Hosting online tournaments is probably also easier for them and everyone else to be able to attend, rewarding in-game content code is also cheaper/easier than real hard content, so.. Yeah, it sounds nice
And if you had to register your adress, why not posters and other lightweight goods - but I would rather have in-game content over posters