Indeed, most large CDNs will ship you, for free, hardware to install at your ISP PoP in order to reduce both theirs and your bandwidth costs. Google does it, Ak

Indeed, most large CDNs will ship you, for free, hardware to install at your ISP PoP in order to reduce both theirs and your bandwidth costs. Google does it, Akamai does it, Netflix does it. Assuming a decent cache hit ratio, this drastically reduces bandwidth on expensive, percentile-billed Tier 1 upstreams that most ISPs still depend on - especially in the US, where truly neutral internet exchange points are rare. Interestingly, the 1TB cap is exactly what ISPs use to plan for and calculate their percentile-billed upstream commitments, as a 1TB cap corresponds to a sustained 3Mbps usage.