Manipulation techniques in online Retailing

I was Sitting with My girlfriend in a bar and then suddenly started a discussion on "how to start a new online business". New Business Like Online Retailing and E-Commerce Like Amazon, Flipkart, etc. then we Checked few retailing Sites online and try to find out how these online Retailers create unnecessarily Consumer Demand. As my Girl-friend has management Degree in marketing background She explained to me How These Online Retailers allure Customers to buy any item.

There Are a number of techniques used by online retailers as below:

1) As the potential Customers Visit Online, It Shows a notification on site how the Customers are Saving their Money while Shopping on this XYZ.com. This is a common technique faced my many online Shoppers. 

for a moment Consider you have visited XYZ.com and choose an item to buy then you have noticed a message below that item price that "you have Saved 550 Rs", thus customer get happy and buy instantly without knowing the actual price.

2) online Retailing Sites uses Cookies to store Customer Browsing history, whenever we Search any item online, Cookies Saved that item Details. We usually Encounter the same item Details as an Advertisement on Different Sites, Which Attract Customers with various Discount offers.

3) Few Online Retailers use Fake Messages that manipulate Users into Buying Items. They provide online Buying offer, discounts, cashback, etc to retain their customers and influence them to purchase items from their online Store.

4) Few of the techniques are Clearly Deceptive as online trailers show bright images of items to attract Customers but when they Try to buy them it shows "item has been sold out" or "Only Limited items are in stock" which influence customers to buy that item without knowing Actual prize. Sometimes there are few online retailers which make it easy to place an order but Cancellation requires a long procedure. 

 Above all make me clear about the Digital Techies Used to Allure Customers and influence Customer Behaviour for Online Shopping, which Could be Necessary and Unnecessary for the Customer Use.