In simple terms, the Content Delivery Networks make use of severs at multiple locations around the globe, each of which mirror the web content, thus improving the page load times while also reducing the load on the main webservers.

There are many direct and indirect advantages of using a Content Delivery Network, and some of them are as below:

1.Improved page load times and faster serving of content

One of the most important benefits of a Content delivery Network is the faster serving of content, which improves the Quality-of-Service for the visitors of the website. Apart from this, a performance lag can also lead to customer dissatisfaction and can result in reduced stickiness of traffic. The increased performance has the following advantages.

a.Higher Conversion rates

A faster website will lead to better customer satisfaction, and thus improves the conversion rates. Moreover, a slow website also turns-off many of the visitors and thus can adversely impact their browsing habits on the website.

There were some studies done by Shopzilla and Mozilla, and based on these studies, by tweaking their pages and just improving load-times (and not changing anything else), Shopzilla observed a 7-12% increase in their conversions, whereas Firefox reported a 15.4% increase in downloads.

b.Better SEO Ranking

Various search-engines including Google have already announced that they would consider page-load time as one of the aspects of their ranking algorithms. Owing to this, a faster website will result in better search-engine rankings and thus more organic traffic.

2.Better Scalability and Reduced Load on web-servers

Another benefit of using a Content Delivery Network is that by distributing the traffic based on the location of the visitors, there are fewer requests on the web-hosting servers. And since the data is served from multiple locations, it helps in ensuring uptime and reduced performance lags even when there are bursts of traffic.

3.Increased Security

The use of CDN also helps in protecting the websites against attacks like massive Distributed Denial of Service (DDoS) because the CDN redirects the traffic requests to different edge servers and thus reduces the impact of the attack.

4.Reduced Bandwidth and Storage Costs

The final advantage of Content Delivery Networks is that it reduces the amount of bandwidth and storage that needs to be bought from the web-hosting. Since generally a large amount of the website content will be served by the CDN, it reduces the amount of storage and bandwidth that needs to be bought from the web-hosting service.

To summarize in brief, the major advantages/benefits of Content Delivery Network include better performance, website availability and uptime, DDoS protection and in some cases reduced bandwidth charges.

Sources:
1. http://blog.mozilla.org/metrics/2010/04/05/firefox-page-load-speed-%E2%80%93-part-ii/
2. http://dejanseo.com.au/speed/