If you use Brave News (to display a RSS feed), you get “news” about Brave’s functionnalities. They appear as any other widget in your feed, but are marked as “Advertisement” on the upper right corner. Here is an example from my feed : https://imgur.com/a/RJV2Px2 .
Looks like it’s not the case anymore, but when I opened a new tab, some time ago, I used to get ads from Binance or other cryptocurrencies exchanges displayed as “cards” on the right of the window. Right now, I only get “cards” showing about “Brave Talks” or rewards, but it used to be advertisement about other products, such as Binance or other cryptocurrency company.
I can’t reproduce it right now, but some “new tab” backgrounds are (or were) also advertisement for crypto-related products.
There was also a controversy some time ago where they were injecting their own referral link when you typed a cryptocurrency exchange’s URL on the search bar : https://www.androidpolice.com/2020/06/07/brave-browser-caught-adding-its-own-referral-codes-to-some-cryptcurrency-trading-sites/ . They stopped after it got viral.
At least they are tagging their ads as such, but it’s weird how you can’t block any of it when they decide it’s there.
I opted out and I still see ads. That’s the problem.