A team of researchers measured the amount of third parties called as websites include third-party scripts.
Using this concept, we show that including a single third party can lead to subsequent requests from up to eight additional services. Furthermore, our findings indicate that the third parties embedded on a page load are not always deterministic, as 50% of the branches in the third party trees change between repeated visits. In addition, we found that 93% of the analyzed websites embedded third parties that are located in regions that might not be in line with the current legal framework.
Some solid data to stress just how dangerous it is to embed third party code in websites.