CDN is short for content delivery network.
A content delivery network (CDN) is a system of distributed servers (network) that deliver webpages and other Web content to a user based on the geographic locations of the user, the origin of the webpage and a content delivery server.
This service is effective in speeding the delivery of content of websites with high traffic and websites that have global reach. The closer the CDN server is to the user geographically, the faster the content will be delivered to the user. CDNs also provide protection from large surges in traffic.
Servers nearest to the website visitor respond to the request. The CDN copies the pages of a website to a network of servers that are dispersed at geographically different locations, caching the contents of the page. When a user requests a webpage that is part of a content delivery network, the CDN will redirect the request from the originating site’s server to a server in the CDN that is closest to the user and deliver the cached content. The CDN will also communicate with the originating server to deliver any content that has not been previously cached.
The process of bouncing through a CDN is nearly transparent to the user. The only way a user would know if a CDN has been accessed is if the delivered URL is different than the URL that has been requested.
Content delivery networks are used for B2B interactions and in serving content to consumers. Today, as more aspects of daily life move online, organizations use content delivery network to accelerate static content, dynamic content, mobile content, ecommerce transactions, video, voice, games and so on.
But what happens if I want to run traffic from Argentina? or South Africa? or Australia and India?
The visitor clicks the banner when he’s in India, then he’s routed through the DNS to my landing page hosted in the USA and then he clicks the button to the offer and goes back to another server hosted who knows where.
The response time could be enough for the impatient user to close their browser and surf somewhere else. But I’, still being charged for that click.
Originally the CDNs were being used to host heavy things like images, CSS, scripts and more, but because many times affiliates use simple landing pages (especially for mobile traffic) you can host the whole landing page in the CDN as long as it doesn’t use PHP.
Also, because the content is distributed in several servers it means the traffic is balanced instead of saturating just one server that could go down anytime while I’m sleeping and there goes a few hundreds or thousands from my wallet until I notice it.
Dedicated server receiving 1 million hits per day from all around the world
You get ( example):
USA Node receiving 300,000 visits, European node receiving 250,000 visits, China node receiving 150,000 visits, African node receiving 150,000 visits and Australian Node receiving 150,000 visits.
Everyone gets the content faster and you get more clicks/conversions = more profit from your traffic.
Plus, you know anything can go wrong with your VPS or dedicated anytime and you might not be able to fix it ASAP. While if a node goes down on a CDN (very unlikely) the traffic gets routed to the nearest working node.