Pingdom is big on monitoring websites for downtime and is truly an amazing service. You can pay a monthly fee to have Pingdom monitor your own site, but they also have a service called Pingdom GIGRIB that currently monitors 2,000 websites across the Web.
The GIGRIB service is unique in how it works, and is actually free. The reason it doesn’t cost anything is because you have to setup your computer to run the software, which will monitor other websites for downtime. For every one hour that your server does checking for downtime on other sites, you receive five hours of checking from other servers. I like to compare it to the BitTorrent network where the work is distributed across thousands of computers.
This is the same service that we mentioned a few weeks ago that monitored the downtime of the top 20 sites on the Internet. If you use the GIGRIB service, your downtime stats are also made publically available, which makes it fun watch for downtime on some sites like YouTube (who has been down for 3 hours and 15 minutes so far in April).
On the Pingdom blog they did a little bit of an extrapolation to get the total downtime of all active sites on the Internet. The average downtime for 2,000 of the sites on the GIGRIB service was 1 hour and 59 minutes for March alone. Then they used the estimated 51.3 million active sites on the Internet (according to Netcraft) to come out with a whopping 4,239,375 days of total downtime. That is 11.614 years worth of downtime in just one month!
Remember, if a hosting company boasts a 99.9% uptime guarantee that means there can’t be more than 44 minutes of downtime in a single month. If you do have more downtime than that you could be eligible for some sort of refund.