Kind of a neat idea but with services like preev.com, I guess I just don't understand how this could be helpful? getting the price in seconds compared to getting it every 30 minutes just doesn't make sense to me. whats the advantage to using @nowbitcoinpirce?
I think this goes for those people who have just invested in the btc and does deal in on daily basis like speculating, trading etc. Their will be people who are already in their full time job and may not get access or time to check rates etc. So this update on their mobile timeline will just give a snapshot of the current prices at regular interval what is happening.
OP - Also this could be changed to an hourly basis if half an hour frequency is too much I think?