We use NewRelic and Pingdom as well. Where Rearview really shines is creating monitors like this: 1) control charts to alert when a process deviates from a range of 3 stdev above or below the mean based on historical data (e.g. purchases/logins are lower than expected, process failures are higher than expected, etc.), 2) deployment triggered monitors that automatically analyze data before and after a deploy for shifts in mean or increases in variance (e.g. do we see more login failures after this deploy, do we see more 4xx/5xx responses, did page load time increase, etc.), 3) response time monitors... while this seems straightforward enough, Rearview can not only tell you when a service or page response time has exceeded some statistical limit, it can also present you with more information regarding causes (e.g. this process is slow because of an issue with the database, redis, a dependent process/service, etc.), 4) it allows you to use SPAN as a means of monitoring load time or response time (SPAN is the 95th percentile - the 5th percentile and it give a much more accurate representation of what users experience than mean or median, 5) process efficiencies can be checked by making sure they complete on time and execute the expected number of commands (e.g. sent email, updated databases, etc.), and many more. Basically you are only limited by your imagination and coding skills. Of course the other benefit is in performing similar monitoring on business metrics and not just application performance (e.g. is funnel performing as expected/needed, are our customer tools being used on a regular basis, are our marketing campaigns paying off, etc.)