With increased consumer demand for streaming content such as video on demand and peer-to-peer file sharing, demand for bandwidth has increased rapidly and for some ISPs the flat rate pricing model may become unsustainable. However, with fixed costs estimated to represent 80–90% of the cost of providing broadband service, the marginal cost to carry additional traffic is low. Most ISPs do not disclose their costs, but the cost to transmit a gigabyte of data in 2011 was estimated to be about $0.03.