Google Assistant was considered to be free from advertising. However, it now seems that there are properly labeled sponsored links for a narrow set of Google Assistant search results which are related to air travel. Read more at voicebot.ai
A digital agency in Australia seemed to have recently discovered that a search using Google Assistant on a smartphone yielded several sponsored links. Voicebot seemed to recreate the search from various cities that asked how long does it take to fly to fiji.
No general answer was provided to the question but it instead suggested flight times together with prices to four Fijian cities. A similar experience was also created for Google Assistant searches asking regarding how long it takes to fly to Cook Islands, Jamaica and Malaysia.