It's 3 a.m. Do you know how your website is behaving?

If you run an online business of any kind, you should, because downtime and poor website performance not only causes lost revenue, it also can lead to a loss of reputation and loyalty.

Fortunately, keeping tabs on your website 24/7 is an easy task thanks to services that automate the process of monitoring your website around the clock.

If your website goes down or slows to a crawl, these services will automatically notify you using a variety of methods such as email, pager and SMS.

Many of these services enable you to monitor specific services/protocols (i.e. web, email, etc.) as well as custom scripts on your website.

Some even permit the configuration of advanced alert criteria and provide for escalation procedures that alert different people if the website remains down after initial alerts.

Here are 4 popular monitoring services:

AlertBot
Monitors: All major protocols, custom scripts
Alert Delivery: Email, SMS, paging
Reporting Tools: Yes
Escalation Rules: Yes
Cost: Based on protocols monitored and frequency of checks

Alertra
Monitors: All major protocols, custom scripts
Alert Delivery: Email, phone, SMS, paging
Reporting Tools: Yes
Escalation Rules: Yes
Cost: Based on protocols monitored and frequency of checks

AlertSite
Monitors: Most protocols, custom scripts
Alert Delivery: Email, phone, SMS, paging
Reporting Tools: Yes
Escalation Rules: Yes
Cost: 30-day free trial, plans and pricing provided upon request or after trial expires

Uptrends
Monitors: HTTP, HTTPS, POP3, DNS, TCP connect, match and PING
Alert Delivery: Email, SMS, RSS, IM
Reporting Tools: Yes
Escalation Rules: Yes
Cost: Free 1 website plan available, other plans start at $23/month