Imperfect comparison: promotions, rebates and coupons prevents directly comparison

Comparison-shopping helps consumers find best price for a product. Does that mean shopbots will eventually become the first stop of online shopping? At least for now, it is not.

Online stores use a lot of tricks to attract consumers by offering lower price than those listed by shopbots. For example, the rebates. There are a few rebate sites like ebates.com actually offer rebates for a wide range of partnering online stores. There are also quite a few deal sites offer coupon and rebate information about online stores. To name a few, dealnews.com, dealsea.com, techbargains.com, mrrebates.com, etc.