[tnmom]

Their marginal cost for you using otherwise-unutilized capacity is near zero; probably just power really. So if it’s a choice between getting $0 and $0.1 for a $1/hr instance, that’s an easy choice.

You just have to be sure to make the spot stuff juuust unreliable enough that people can’t run their full workloads on it all the time.

[skeeter2020]

if you've got the engineering in place for distributed fault tolerance you can run a lot of your workload on pre-emptable spot instances. There's an entire "as a service" product space that does this, abstracting away the challenging parts and arbitraging the difference

[_zoltan_]

could you name a few such aaS service?