The ultimate aim of any company that runs a shopping website is obviously to compel potential customers to purchase or pay for the products and services on offer. SEO is a critical component of a given shopping website's potential success because customers are much more likely to open the website if they see it among the highest positions in Google's SERPs, so the websites ideally would be fulfilling every conceivable SEO-related step. At the same time, there are all kinds of subtle tricks and surreptitious methods the owners of these websites can willfully pursue to deceive customers; these typically involve modifying the UI of the site's layout and the UX of the site's procedure.
A fairly minor "dark pattern" that a website can use to pressure its customers into participating is to force them to create an account if they want so much as to even see the products on offer. Likewise, the account creation features of many websites offer an option to subscribe to a newsletter that will be delivered to the user's email address — but this is often enabled by default so that the user is likely to unintentionally invite many more emails than they would prefer to receive. Storefronts sometimes place testimonials next to certain products, which would be acceptable so long as proof of each testimonial's alleged provider can be provided and sourced. If it is not, the possibility will remain that the message has been fabricated.
The closest that these dark patterns may come to criminality is when they are used to deceive customers into making extra purchases without them realizing it if they are not attentive. A very cheap product that may not have been specified by the customer at any point may be inserted into their digital shopping cart shortly before they commit to their purchase. Likewise, an offer to remove a website's shipping fees for a lengthy period of time can add a large fee to one's shopping cart; instead of being clearly listed next to the offer from the very start, this fee may be hidden behind a "Learn More" button. For more information click here https://webtransparency.cs.princeton.edu/dark-patterns/.