Since we don't know Google's hosting costs, let's calculate it in a different way - from the published rates of Amazon S3 service. Note that this calculation is primarily focused on storage and bandwidth costs.

Here are some stats to work with:

- average video size on YouTube is 10 MB (maybe slightly dated)
- videos served per month 30 billion
- 20 hours of video uploaded each minute, or 864,000 hours of video per month
- average size of 1 hour of video = 0.5GB (calculated at bit-rate of 1150 kbps for VCD quality vide0)

Data transferred out per month to view the videos is:

30billion * 10MB = 300 billion MB = 292,968750 GB

From the Amazon S3 calculator, this comes to $29 million/month.

Cost of videos transferred in per month is:

0.5GB * 864000 = 432,000 GB

From the Amazon S3 calculator, it is $43,200/month.

Data transfer out dominates the data transfer-in costs.

Storing the new video each month costs $66,000/month. (Cost of holding previous videos is not calculated since I don't have that data).

The grand total is around $29,366,380/month or about $352 million per year. The real cost to Google would be lower than this (perhaps by 10-20%), but $352 million seems to be the upper limit for this year. This is quite similar to the estimates made by Credit Suisse report.