Real User Measurements

Chapter 3. RUM Never Sleeps

Those who speak most of progress measure it by quantity and not by quality.

George Santayana

Tammy Evert, a prolific writer in the area of performance optimization, donated the title to this section. She uses the term to signify the vast amounts of data you typically get in a RUM implementation. I use it in the same vein, but it is worth noting a comment I received on a blog I wrote about this subject. The commenter noted that actually, synthetic monitors never sleep, and that a RUM implementation can (as mentioned earlier) be starved for data during the nighttime or if the app just does not have enough users. So how many users are “enough” users? How many measurements are sufficient? Well, if one of your objectives is to have a strong representative sample of the “last mile,” it turns out you need a pretty large number.

There are use cases for RUM that utilize it to capture the last mile information. We discussed in the introduction why this might be important, but let’s take a minute to review. The last mile is important for Internet businesses for four reasons:

• By knowing the networks and geographies that its customers are currently coming from, a business can focus its marketing efforts more sharply.

• By understanding what networks and geographies new customers are attempting to come from (emerging markets for its service), a company can invest in new infrastructure in those regions to create a better performing site for those new emerging ...