Conversion rate is too less for me. Active time spend on website with source as Yahoo (from my add) is too less. Order conversion is close to 1%
Depends on your market. Yahoo is more "consumery" and has more women. Yahoo has awesome conversion rates for e-commerce. Also, it doesn't really matter which channel has higher conversion rate. If the conversion rates are higher, raise the bids. If lower, decrease your bids.
"More consumery", e.g. B2B shoppers use Google, business.com, thomasregister, etc. Contrast that with B2C where our low avg order size e-commerce clients tend to get a nice little jump in Yahoo (% of all orders is higher in the Yahoo channel than their market share would dictate).