For the "how" and the "what", in the future, I bet ads platforms will ask you to write an long essay about what you sell, and they will automatically generate many different ads with GPT-2 (probably in real-time, to mix some content of whatever the viewer is browsing at the same time), and everything will be automatically A/B tested, segmented, adjusted, etc with reinforcement learning.

Even better, no need to write an essay about your services or products, Google already know everything about it by scraping your website, so just point to the URL, and done