First, you enable e-commerce for each view in which you want to see your data. Second, you add code to your own website by editing your HTML home page to collect the eCommerce data.
follow these steps:
Sign in to Google Analytics, click Admin. In view column, Click eCommerce setting - > Enable eCommerce to ON - Then Save it.
Yes its really useful thing to identify your website audience and interest.
You need to enable Ecommerce for each view in which you want to see the data. Sign in to Google Analytics. Click Admin, and navigate to the view you want. In the VIEW column, click Ecommerce Settings. Set Enable Ecommerce to ON. Click Save