From their site: Pingdom has a very strong and narrow focus. That focus lies on covering the uptime monitoring needs of 90% of the companies in the world. Instead of branching out into other areas, we will instead place all our efforts into maintaining the best uptime monitoring service available. With Pingdom, any problem with your website will be discovered the minute it happens. You will be immediately alerted so you can take action before it affects your business. You will also be able to see detailed statistics of your website performance, giving you a historical record of all incidents.