about ROI

three different ways to ROI:Google analytic,tweet-meme analytic,post-rank analytic.
they both have pro's and con's
RIO is a good way to provide the supplier the information about their sales
it results a cost reduction,and it will generate more revenue.
but still it has some disadvantages
it can't tell you how much is new customers' to buy or old customers~
but it still a pity that there are so many companies don't use it and so it's so useful for companies to know their return investment