In another informative talk, Andy Davies looks at how you can measure the cost of a particular third-party script (just after the 4-minute mark).
- Test a page in WebPageTest
- Repeat with selected third-parties blocked
- Compare the two (filmstrip) results
This process can help illustrate performance and UX tradeoffs being made, but Andy also suggests feeding those results into a RUM (real user monitoring) dashboard to understand the business impact.
“What if I was a second faster? How many more conversions would I get? You can begin to translate that user-experience impact into pounds and pence.”
This step had never occurred to me, and after a teeny bit of research on RUM tools, I realized that quite a few past clients likely had this data available, I just didn’t know what to do or how to ask for it. A post on the Soasta blog (via Charles Vazac) further illustrates utilizing RUM for these purposes.
“What if my digital property had better performance? How would that affect the bottom line of my company?”
Next, I’m going to try and get some experience with RUM tools and work with a client to get these sorts of data points. If you’ve got any screenshots or stories using RUM tools to do this sort of thing that you can share, please give me a holler!