#### talk
## Why performance isn’t evenly distributed?
In his talk, [Ilya Grigorik](https://twitter.com/igrigorik) highlights the critical fact that most of performance advice and tooling **doesn’t reach a significant portion of the users of the Web**. Learn how to ensure performance know-how is evenly distributed on the example of image optimisation.
[]()[performance.now().reject(reasons) →](https://www.youtube.com/watch?v=vtIfVPtN6io)
#### article
## Get started with web performance
Starting your journey with web performance *feels* overwhelming. **Even seasoned performance experts often struggle with keeping up.** We wrote an up-to-date guide providing all the concepts you need to know to be effective in performance work, no matter your level of expertise.
[]()[Getting Started with Web Performance →](https://calibreapp.com/blog/get-started-with-performance)
#### article
## Learn how to implement fast, better ads
In his in-depth case study, [Christian Schaefer](https://twitter.com/derSchepp) explains mitigating the huge performance cost of implementing ad networks. He covers lazy loading, layout stability, disabling ads on slow networks and ensuring user private information remains safe.** If we can’t have an ad-free Internet, let’s at least make ads good.**
[]()[Dealing with Ads in 2020 →](https://schepp.dev/posts/ad-integration-in-2020/)
#### article
## Convince your boss to care about performance
Convincing stakeholders to allocate time and resources to performance work when they don’t understand its impact and importance can be very difficult. In his article, [Armel Pingault](https://twitter.com/armelpingault) explains how to create a proof of concept to **back up your performance advocacy with data.**
[]()[How to convince your client to focus on Web Performance →](https://medium.com/@armelpingault/how-to-convince-your-client-to-focus-on-web-performance-a-case-study-35f12385689)
#### article
## Know which CSS is safe to remove
Numerous tools audit the amount of unused CSS, but **none of them can crawl your entire application considering multitudes of states it could be in**. Here, [Chris Coyier](https://twitter.com/chriscoyier) explains the bottlenecks of automating the optimisation of CSS.
[]()[How Do You Remove Unused CSS From a Site? →](https://css-tricks.com/how-do-you-remove-unused-css-from-a-site/)
#### new in calibre
## What Calibre released last month
📚**Release Notes: November**
Here’s our monthly roundup of what was released in November: Main Thread Task Execution Timeline, making your Single Page Tests results private and more.
**⚡️Main Thread Execution Timeline** allows you to analyse JS main thread activity quickly. You can spot which scripts block the execution of your apps and make improvements to what your users experience.
[]()
