I believe that twitter campaign is not as effective as the signature campaign because Twitter is full of fake, bot accounts and it is hard to find a person who has many real followers related to bitcoin gambling. Anyway, if you are the good manager who knows how to maintain the campaign, it will be easy to advertise your site to everyone
Signature campaigns mostly are not that effective either. Most services that starts signature campaign don't get as much as a good result unless the service is really interesting for people to click it and check what it is that they can see in the sig ad.
Twitter campaogn and facebook campaign can be effective same as signature if you will manage it properly.
Both of you are partially right and wrong.
1. It is true that twitter are full of fake users, bot controlled account and useless spam no one ever reads. But twitter audit is good tool to verify that.
2. If service is not good, not interesting or is a simply copy of some other, well established service i.e. another Dice site then promotion of such service won't be effective no matter what, in the first place.
I think that both Twitter other social media as well as signature campaigns can be good marketing tool.
The best way is to use them all, because by doing so you will target different groups of users.
