Personal consumer data has become the oil of the 21st century. American companies are expected to spend close to $20 billion on consumer data in 2018 (New York Times 2018). Data trackers are the main way advertisers gather this valuable consumer data.
A previous study of 144 million page loads in 12 countries found that 77.45% of page loads contain trackers (Macbeth 2017).
On average websites take more than twice as long to load with trackers than without (see Figure 1). The average top 500 website loaded in 19.3 seconds with trackers. With trackers blocked the load time dropped by 55% to 8.6 seconds.
The distribution of page load times of the top 500 websites is shown in Figure 2. Only 17% of the pages tested loaded within 5 seconds. Nearly 60% of pages loaded in more than 10 seconds, 18% of pages loaded in more than 30 seconds, and nearly 5% of pages took more than one minute to load.
The study showed a direct relationship between the number of trackers and page load time. The more trackers the slower the page load time. The closest quadradic model of the relationship between trackers and page load time found a compounding effect for trackers. Each additional tracker adds about 2.5% to page load time.In addition, the researchers found a "piggybacking" effect, where trackers load other trackers not originally on the site, further compounding the slow page load times.
The most tracked websites in the study showed the cumulative effect of trackers. Seven of the top 500 websites had over 100 trackers present (see Figure 3).
The slowest domains were on average 10 times faster when trackers were blocked and users saved an average of 84 seconds per page load (see Figure 4).
Raymond.cc conducted a test of 10 ad blocking extensions on performance (Raymond.cc 2016). The fastest ad blocking software improved page speed by more than 3 times (uBlock Origin). Overall, the three best performing ad blocking extensions were uBlock Origin, Ghostery, and Adguard. uBlock won in raw page speed (see Figure 5) and CPU usage. Ghostery won in peak memory used in Chrome.
The use of tracking software has a significant compounding effect on website performance. Each additional tracking widget slows web page load time by 2.5%. For the average top 500 website, page speed was greater than 2 times faster by blocking tracking. The 10 slowest websites tested were 10 times faster without tracking. Reducing the number of trackers on your website can give a significant boost to web page speed.
By website optimization on 19 Dec 2018 PM