I created my site two years ago as a hobby project, I was both interested in how SOL worked and I also thought that storing the race history hourly would have value for the players. I mainly have developed it to fill my own needs, but there have been features I have added by request which I don't consider so important for myself.
As I didn't want to keep the data just to myself, I needed a public server for hosting the service. I got one from Hetzner.de for 49 euros per month. So far for two years I have been paying the server myself and plan to continue doing so.
However, when testing the Donate-button I thought that perhaps some of the frequent users of my site might want to share some of the costs of the server with me and the button would be a way for anyone willing to do so.
Some thoughts about paying:
SOL server is funded by SYC membership fees, if you consider spending money on your virtual sailing hobby, please pay SYC membership first. If you think the playing is worth more than that, you can then donate money to sailonline.org or me. My site is useless without SOL.
Donations or lack of them won't affect the way I run my site, I plan to continue supporting it and slowly developing it as I have done so far. I also reserve the right to close it whenever I wish (not that I have any plans to do so now).
49 euros per month is not the cheapest server you can get. But I needed a server big enough for storing the data and handle weather data etc. With current usage the server I have now will hopefully have enough power and space for next 2-5 years.
I know there are many others doing valuable work for SOL for free, most of them don't have direct costs from doing so though. I don't consider my work more important than others, but I also have costs for running the service. I don't know if sol.brainaid.de costs something to run but if it does, I wouldn't think it would be wrong to donate some money for that service as well (if the administrator chooses to create a way to do so)
So if you consider donating, how much would be suitable? From usage statistics I believe that the site has perhaps 50-100 frequent users. My yearly costs for running the site are 588 euros. So if roughly 60 users pay 10 euros per year I hopefully could be in a position that I am not spending money myself to keep the service up. How much you possibly want to pay is totally up to you though.
And if you for some reason don't want to donate anything, that is perfectly fine. The donate is just a way they can share the costs of running my site. Using it is still completely free and I am very pleased that so many have found it useful.