- Charge $0.15/GB for storage
- Charge $0.17/GB for bandwidth
- Pay a peer $0.01/GB for storage
- Pay a peer $0.02/GB for bandwidth
The main issues we can see with this model are that for the lower allocations of disk space - provided by the user - and slower internet pipes, the user takes home a pittance (approximately $4.83 for a 1mbit connection with 50GB storage space). However, for more powerful connections with higher quantities of space, a user can be more than doubling or tripling the cost of their internet connection every month (with prices falling so rapidly, especially in the US). With a 50mbit connection, and 50GB storage, a user can be taking home approximately $220 per month. Assuming 50mbit will be $50 throughout the US, following the lead of a town in Minneapolis, they have quadrupled the cost of their broadband connection - assuming the CDN uses their connection for the amount of time they allocate it for (and also assuming their computer is left running 24x7). Note: The Discount Factor in the spreadsheet model above is used to reflect the amount of time the user will allow the CDN to use their computer and bandwidth. So a 0.70 discount factor means that 70% of the time the CDN will have access to the users computer and bandwidth. Just to do a quick comparison to the large CDNs (in terms of their cost structure), here is something to think about. As far as I can tell, the largest line item expenses that the ‘non-fibre-owning CDNs’ have is the cost of bandwidth. Looking at Limelight Networks (LLNW), we see that their Cost of Revenue was approximately 64%. An unscientific comparison with the above model highlighted, shows our Cost of Revenue being 6.7% for storage, and 11.8% for bandwidth = approximately 18.5% of Revenues. Even if our model inputs were doubled ($0.02 for storage, $0.04 for bandwidth) cost of revenues would be approximately 37% (i.e. 50% lower than the traditional CDN). The CDN business is a multi-billion dollar business. With a model like this, scaling becomes more of a software problem - than a hardware problem - which is a beautiful place to be. You scale on the backs of ISPs and users are responsible for maintaining their machines. It’s Google’s Adsense business model implemented as a CDN - in short. Please feel free to tinker with the numbers, and leave comments for how I can improve the model. Disclaimer: This post assumes a number of variables, all of which are not fully fleshed out - due to the difficulty in fully conveying the complete picture in a simple blog post.