asher02 - 10:19 am on Jun 22, 2012 (gmt 0)
GA data is valuable for Google and I think that if they do not use it now they will someday. I'm using GA for all my eCommerce website as I want Google to see that my customer are happy, interested in what I have to offer and place orders.
Google can collect data from many sources, however when it comes to conversions rates, sales , product performance etc GA is probably the only way they can distinguish sites that converts to site that don't.
GA is a really good in collecting valuable data about my sites and I use the data regularly to improve my sites. Regarding your question:"Should I use it?" I say YES, If the stats you see are good, share it with Google. It might not benefit you (I think it does)but it will not harm you.