I'd rather set up login functionality on my own server. If you use a third party service, their downtime becomes your downtime. Worse, you're injecting another company into your relationship with your users. If that were necessary, I'd choose one the customer was already familiar with, like Google, Facebook or Twitter.
Setting up login isn't very difficult and libraries exist for most webdev languages to make it even easier. It's definitely not worth 5% of my revenue.
I'd rather set up login functionality on my own server. If you use a third party service, their downtime becomes your downtime. Worse, you're injecting another company into your relationship with your users. If that were necessary, I'd choose one the customer was already familiar with, like Google, Facebook or Twitter.
Setting up login isn't very difficult and libraries exist for most webdev languages to make it even easier. It's definitely not worth 5% of my revenue.