A great Twitter campaign or just a brand campaign?

Some Twitter campaigns from companies and brands are outstanding and become brilliant case studies. This one from a Turkish telecoms company keeps users engaged on the micro-blogging platform by using most common Twitter features. Just by removing post-it’s for a chance to win the phone, Twitter users spread the word around the new technology with 56,000 Tweets around the competition over the 3 days that the activity was run. The “crossword puzzle like” competition ended with users trying to get a celebrity to Retweet them to win the phone. Nice idea…!

However, there are some questions that arise from this Twitter campaign case study for me…
Are such campaigns only possible with heavy Twitter and mobile users?
Is this campaign buzz getting out of the inner circle of the heavy social web users?
What is the long lasting ROI effect this creates (if at all it does)?
Are such campaigns more efficient from a branding perspective than using PR briefings?
I am sure you can think of many more questions…, right?

If this is an outstanding social media case study, then it would be good to hear what makes this campigns so compelling? Wanna watch the video and give me your views? Really looking forward to it…