My advice to anyone is to give what you think the site is worth to you, and that you can afford to give, without impacting your life in any sort of negative way. There's no right or wrong answer, anything is helpful. Trust me, in no way are we in danger of getting more donations thaN the site has cost us to create and maintain for these past 5 years. But, if you are asking what the site cost to run her the amount of users we have, on an individual basis… I don't have an answer for that. I suppose we could put something like that together.
Any number of discussions we've had have been about sustainability. It would be good to have a real idea of what that sustainability looks like, particularly since this site is so social and interconnected that we're starting to look more like "shareholders" than "users." Hubski has been in negative earnings for a long time and it's probably time that we, the shareholders, shoulder some of the burden.
Hubski should do a NPR style donation drive twice a year. Every fifteen minutes the tight rope walking monk should talk about how important user contributions are. Your only options are to wait for him to go away knowing he'll be back sooner than you'd like or browse Reddit for two weeks until the drive is over.
Check out the donation page at lichess.org. Might be a bit overkill for Hubski but it works well for them.
Maybe. I'm just glad people will have a way to feel even more connected. If it can help us make actual swag that we can share, all the better. That'd be awesome.