Linuxmint.com is hosted by Servage.net. The server is shared with other customers. When linuxmint.com receives too many visitors, the number of requests on the server goes higher and this generates a higher CPU load. Servage.net simply monitors the number of requests ran within a day, and if these get too high, it suspends the account for some amount of time. Basically, linuxmint.com will go down everytime the traffic on this website will get too important.
To solve this problem we're looking at dedicated hosting. However, Servage.net was more or less a $10/month option and the google ads we used could cover that. Dedicated hosting will probably be around 50-100$/month.
If you can make a contribution and help us on this, even if it is $20, $5 or even a simple $1 donation, together we should be able to afford a dedicated host.
A donation button was added to the main page: http://linuxmint.com/
Also, if you know of a good dedicated host, please tell us... we've never required one before and we don't really know where to look for.
Thanks for everybody on this. I hope this problem will be solved soon. In the meantime, our website and forum will still be up, but probably only half of the time