Watching videos on YouTube

Q: I read one of your fatwas entitled “Nose surgery to straighten one's nose” where someone asked a question mentioning watching a YouTube video of some Shaikh. As you replied to the answer, you also added that “ Viewing YouTube videos is impermissible. If you had viewed it, then you should make taubah and refrain from repeating this sin in the future”.

I have a small question, rather request a clarification whether it is a sin viewing any video (including of Ulama) or particularly those illicit immoral videos.

Giving the buyer a gift for purchasing over a certain amount

Q: A website is selling books at a discounted price. Whoever buys books for more than R250 gets a free bookmark. Whoever buys books for more than R750 gets another book free. Whoever buys books for more than R1499 gets free home delivery.

I want to know if transactions like these are valid where the seller gives a gift if the buyer buys products of a certain amount of money?