I am making design of e-commerce site and one of specifications was that there needs to be facebook and twitter widgets in site. So my question is "Is there any reason to use twitter and facebook widgets in e-commerce site ?"
On-site social media modules can help retailers drive sales conversion and increase revenues. Here are a a couple of examples:
1) Plum District is getting 35% sales conversion rate using social media on their site (link)
2) Carol's Daughter is getting 8% revenue uplift using social media on their site (link)
A reason to include social media widgets on an e-commerce site would be to highlight promotions or campaigns. For example, including a Twitter widget related to certain hashtag, and you could show the buzz people are generating regarding your promotions/campaigns based on the hashtag popularity, or perhaps just tweets that get sent to your twitter account.
Could also be bad publicity, if a campaign gets negative feedback, but the transparency could earn trust from customers.
I believe it improves the user's connection/involvement with the e-commerce site, and engages them more with hopefully up-to-date commentary and information, hence their experience is enhanced by including the social media widgets.
In terms of design, or look and feel, fitting in with the e-commerce's design, that may be challenging. Not sure if it is possible. But most users that will gain from it will already be comfortable with the social media's look and feel, so I believe it would at least be a good trial.