First off, security is a big deal. You want something that protects your customers' data and minimizes fraud. Ease of use is another factor; if it's complicated for you or your customers, you might lose sales.
Some systems charge a lot for transactions, which can add up quickly. I once set up a payment system for a small business and initially overlooked the transaction fees, which ended up eating into profits more than expected.
Also, think about flexibility. I recently switched to using https://atlos.io/ for crypto payments, and it made the process so much smoother. It’s a permissionless gateway, which means fewer headaches.