Why should I purchase a subscription?

Purpose of SageMathCloud

The purpose of SageMathCloud is to make it easy to use Sage collaboratively and to generate a stable revenue source to hire fulltime developers to develop Sage. Subscription revue currently is enough to pay for server infrastructure but not to cover employee costs. See http://wstein.org/talks/2016-06-sage-bp/bp.pdf for more info about the challenges of funding Sage development.

Reasons you should purchase a subscription

1. Better support. Subscribers get higher feature request priority and more involved support responses.
2. Members only hosting. The free servers are overloaded. They are cheap Google preemptible instances. A side effect of the cheapness is that the free servers are randomly restarted at least once every 24 hours.
3. Use of internet resources in code running on SMC. For example to download data directly to your SMC projects you must have an internet access upgrade applied to each project you want to download data to. To install software in your SMC projects directly from the internet requires an internet access upgrade. The whitelist for sites like Github was removed after abuse by a free user causing Google to temporarily shut down SMC. The $7/month minimum fee has been enough to prevent abuse.
4. Share your upgrades with friends, co-workers and family.
5. Fund improvement of SMC and Sage. Improvements are made daily. The development focus for Summer 2016 is making SMC reliable and high quality for use in teaching. See contribution graphs at https://github.com/sagemathinc/smc/graphs/contributors
6. Help fund the free-tier offering for those who can't afford a subscription.

Making tax-deductible donations to fund Sage development

If you would like to make a tax-deductible donation to support the development of Sage see the University of Washington's Sage Foundation donation page https://www.washington.edu/giving/make-a-gift/?page=make&Code=MATSAG Contact William Stein for more info wstein@sagemath.com

The Sage Foundation account is a UW math department account. William Stein plans to be on unpaid leave for the next two years while he runs this company, during which time he's still fully affiliated with the university, but of course he can focus 100% on building a company. After two years he will have to resign though. However, there are three other faculty members in his department who are Sage developers and ardent supporters of what he's doing, so he thinks things would be fine in two years. Also, he has a very good relationship with the math department itself. He's very much not quitting in disgust, but focusing 100% on his goals with Sage and a business. (He has been trying for a long time to do both and it is too difficult for him to balance competing interests, in various ways.)

The Sage Foundation budget pays for things like the Sage booth at the Joint mathematics meetings, some travel towards Sage Days workshops (especially when grants can't cover the travel, due to US-only restrictions), significant student work on Sage (usually paid at $20/hour), etc. The donations during the last year were a lot more than in all previous years (combined?), and have been $5K from Microsoft Research, $5K from the founder of an internet company, $50K from a retired Apple engineer, $25K from a Wall Street mathematician and a few other very small donations. Donated money doesn't expire, and the university does not charge any fees to administer it (like it does with big overhead fees on federal grants).