Letting customers write reviews on your web 2.0 e-commerce site increases the likelihood others will purchase the product as well.  Provided that the reviews are moderated, quality reviews also increase a website’s search engine rankings because customers are providing content for the website.  The higher likelihood to purchase comes in where customers receive unbiased opinions on the product they’re thinking about getting and shows that other people are using the item, not to mention that your site is also busy and active.

No one wants bad reviews obviously, but if the site is run well, has good products, fast shipping, and good customer service then there generally shouldn’t be many.  Some customers saying they changed their mind about the product and got a quick return may even help others feel more comfortable to deal with the site.  Overall, in web 2.0 development, interaction with the website leads to customers having a better experience and coming back.