I know that the deep web mainly uses cryptos as a means of transactions for people who want to buy things over there, but what type of cryptos are mainly used when making those transactions? Its just a curious question I have in my mind.
That's would be Bitcoin owing to its prominent nature, although ETH is used to owing to its faster transaction rate. But that doesn't mean other cryptocurrencies aren't used, it all depends on the website and their preferences, then on you the customer and the coin you can lay your hands on or the cryptocurrency which is readily available to you at the moment.