Answer:

15. Bandwagon

16. The image states that this product is known by everyone.

17. Card-Stacking

18. The clue words are "Fights 3 types of germs" and "Up to 24 hours of protection". We're not sure if that product will fight the 3 types of germs or if that product will last 24 hrs in your skin, that's why the owner of that product decided to put things like that convince them to buy it.

19. Card-Stacking

20. The clue word in that picture is "Experience Ultra-Fast Connection" but we all know that their internet connection is slow. So they're using it to attract people to use their proudct.