How thuttu.com getting product details with MRP price and current price? and also how they getting money from filpkart, Amazon, Paytm, Snapdeal, etc..
They are very more than likely part of each sites affiliate networks therefore they have access to the respective APIs. As for how they make money, when a user clicks on an item they are redirected to the sellers site, Amazon.com for example, if they purchase that item (or in most cases for most affiliate networks, any item) then they will receive a commission based on the purchase amount.