Behavioral advertising scripts slowed websites and made loading unreliable by 2015.

Evidence

To make matters worse, the technology of behavioral advertising added layers of complexity to the code of any website, causing the system to slow or freeze, and sometimes preventing the page from loading altogether. According to a New York Times study in 2015, despite the fact that every other technology had improved, some websites were now taking five seconds or more to load; and the situation was even worse on mobile phones, with their slower connections. Videos had a way of popping up and starting to play unbidden; and the user looking for the stop button would find it was the tiniest of all, and often oddly located. And something of a ruse as well: if you missed hitting it directly, yet another website would open, with yet more ads. — Tim Wu, The Attention Merchants, 1082

Categorization

• XREF: Connects to the broader internet-history thread in this book on how attention harvesting degrades the very medium it runs on.