Read this quote from Slate magazine on Obama campaign decision to used sms as major campaigning tools:
Green and Gerber estimate that a door-canvassing operation costs $16 per hour, with six voters contacted each hour; if you convince one of every 14 voters you canvass, you're paying $29 for each new voter. A volunteer phone bank operation will run you even more—$38 per acquired voter. This is the wondrous thing about text-messaging: Studies show that text-based get-out-the-vote appeals win one voter for every 25 people contacted. That's nearly as effective as door-canvassing, but it's much, much cheaper. Text messages cost about 6 cents per contact—only $1.50 per new voter.If Obama win, dont forget the part played an army of economists with cost benefit analysis as weapon. Politician, ignore economists at your perils!
