Many hosting companies will boast 99% uptime. This might sound good at first, but if you drill down to outage time, 99% isn’t quite as impressive.
99% server uptime translates into almost 4 days of unplanned outages per year. Whereas 99.9999% server uptime translates into less than a minute of unplanned down time per year. That’s a big difference when you consider that these outages can occur during peak business hours.
Don’t be fooled by advertising hype. Even the smallest amount of downtime can amount to hours or even days. Always ask to see a real time monitor, with history, before choosing a web host.