Stung by instances of rogue sellers on their platform shipping dubious products, online marketplaces are putting in place measures to tighten systems and avoid signing up sellers who can tarnish their brand image. Companies like Flipkart & Amazon poses their employees as "mystery shoppers" and then they check the authenticity of product. They also do the back ground verification of the business entity, VAT, registration, and also the Business owner's verification. They also use the reviews of their customers and termed them as "Defect Rate". if it increases by more than 5%, they are banned to advertise on their website.