Not sure mostly Twitter.
In those days lots of Social Bookmarking site are available on Web...but which is the most powerful and helpful in comparison of all....starting with Digg or Twitter...
I'd say Digg, Twitter is mostly built for the sake of Social Networking,
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Twitter always helps the same percentage (your followers who read it). With Digg that's different, you can get a lot of traffic (a lot of diggs) or your article can die if it gets no Diggs.. which means there won't be any traffic to your website.
I prefer the 'always somethin' method, that's why I'm using Twitter much more over Digg
I'll promote your product through video;
How's that sound? Let me know what you think-
http://www.youtube.com/watch?v=UnD4URzOgTw - VIDEO SAMPLE
I prefer DIGG. It brings a lot of traffic.
Digg brings in a lot more traffic than twitter (if you write/show something good)
Otherwise go for the easy & time consuming option: Twitter.
Digg is best for ranking and better ranking power . You will not find any bad stuuf on it and its good to promote on quality places .
Twitter is also good but on many twitter pages you can see massages like :-
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