They don't want to be a Tier 1. They want to be as close to their users as possible, and the two are pretty antithetical goals. And while they could certainly afford to buy out one of the large networks, it would cost far more than what they are currently paying for connectivity, and they'd end up with a mostly unrelated business unit with thin margins and a lot of competition. While the bread and butter of these Tier 1s is Internet transit, the gravy is in the transport, advanced services, government contracts and so on. And these guys are big enough that they can squeeze the price wayyyy down to the point where the network is hardly making anything off them. They'd also become subject to a bunch of common carrier rules in various countries that they likely want no part of.
Being on a 'Tier 1' frequently results in quite sub-optimal paths, as traffic from the 9/10ths of the Internet not transiting through that particular Tier 1 will route via a major POP which may be 1000s of KM from the user. The Tier 1s only peer with each other in a handful of cities on each continent. They also do not peer with very many other networks, compared to a 'Tier 2', or what is available by connecting to a large peering exchange, which increases as-path length.
So while they have extensive dark fibre, some of which they have built, they would prefer to connect to users with direct peering - or even better, cache boxes within the end user's network - wherever possible, and owning a Tier 1 doesn't really help with that. In the case of a CDN, getting close to the user is exactly what they're selling. So they invest their money where it matters - installing cache nodes around the Internet and connecting to IXPs. CloudFlare for example has 165 POPs now. Google is at 167 peering exchanges. At any of them they will peer with anyone, so that's likely 2000+ ISPs they're directly connected to. Akamai claims they have cache nodes installed in over 2,200 locations.
Bandwidth is cheap, and buying a Tier 1 wouldn't necessarily help their goals, even if it saved them money (which is doubtful).
挣tier1的💴，自己是tier1就是竞争关系了
没必要吧 直接对等接入就行了
帮你贴一个reddit好帖，这应该很接近答案了
他们不想成为一级网络。他们想尽可能地靠近他们的用户，而这两者是相当对立的目标。虽然他们当然可以买下一家大型网络，但这将花费比他们目前为连接支付的费用多得多，而且他们最终会得到一个与他们关系不大的业务部门，利润微薄，竞争激烈。虽然这些一级网络的主营业务是互联网传输，但他们的额外收入来自运输、高级服务、政府合同等等。而且这些人足够强大，他们可以把价格压得很低很低，以至于网络几乎赚不到他们的钱。他们还将受到许多国家的共同承运人规则的约束，而他们可能不想参与其中。
成为“一级网络”通常会导致相当不理想的路径，因为来自互联网上 9/10 的流量不会通过该特定的一级网络传输，而是通过一个主要的 POP 路由，该 POP 可能距离用户 1000 多公里。一级网络只在每个大陆的少数几个城市相互对等。与“二级网络”相比，或者与连接到大型对等交换相比，他们也不会与其他网络对等，这会增加 as-path 长度。
所以，虽然他们拥有大量的暗光纤，其中一些是他们 建造的，但他们更愿意通过直接对等连接到用户——或者更好的是，在最终用户的网络中安装缓存盒——只要有可能，拥有一个一级网络对他们并没有什么帮助。对于 CDN 来说，尽可能靠近用户正是他们所销售的。因此，他们把钱投资在重要的地方——在互联网上安装缓存节点并连接到 IXP。例如，CloudFlare 现在有 165 个 POP。谷歌有 167 个对等交换。在任何一个交换点，他们都会与任何人对等，所以他们可能直接连接了 2000 多个 ISP。Akamai 声称他们在 2,200 多个地点安装了缓存节点。
带宽很便宜，即使能为他们省钱（这很可疑），购买一级网络也未必能帮助他们实现目标。
想到了一个同样的问题“当年Google分布式系统那么牛逼，为什么不先搞云计算”
@merci #4 这话说的没问题吧, 就是因为他看不上云计算, 所以 aws 比 google cloud 强的不止一星半点
他家其实不能算是一个网络 应该是一个中转站