CoinGate is described as 'payment gateway for blockchain payments' and is an website in the Bitcoin & Cryptocurrency category. There are more than 10 alternatives to CoinGate, not only websites but also apps for a variety of platforms, including SaaS, Android, iPhone and Self-Hosted solutions. The best alternative is BTCPay Server, which is both free and Open Source. Other great sites and apps similar to CoinGate are CoinPayments (Paid), Bubble by V0LT (Free, Open Source), Plisio (Free Personal) and iBTC (Free).
If you want to sell digital content online, there's plenty of options out there. However, if you want to sell digital content online without violating your users' privacy in the process, you'll have a much harder time finding a suitable program.
Plisio Cryptocurrency Payment Gateway Plisio is a Payment Service Provider (PSP) for merchants accepting crypto. Plisio enables your customers to pay with Bitcoin, Litecoin, Ethereum, Dogecoin, Zcash and 50 other cryptocurrencies.