I am a little confused by Amazon EC2 Spot price and on demand price.
For example, an On-demand windows instance's price is $0.07 per hour. If I bid on the "spot requests", Do I put down price lower than on-demand price?
Can spot price higher than on-demand price? say $0.08 per hour If so, why do I need to buy it from spot price?
Is it only for the reason that Amazon can guarantee that I will have my instances ready on the date I specific with the spot price, which on-demand service can not assure my instances will be available at that time(Amazon doesn't have enough servers by that time)??