You don't "need" ads, as in there are other ways to do it, if there was some reason to never use ads. But there's no reason, so ads are used too, and are quite

You don't "need" ads, as in there are other ways to do it, if there was some reason to never use ads. But there's no reason, so ads are used too, and are quite effective in that too. And it won't be convenient for a buyer that doesn't know certain offering exists. I.e. if I don't know such thing as wireless headphones existed, I couldn't effectively look it up and seek reviews for it - somebody should tell me first - dude, did you know you can get rid of those annoying wires and just buy wireless ones? Now, did I "need" them? Strictly speaking, no - I could very well have lived all my life with wired ones and be fine. But wireless are better for me, so why should I resent someone who tries to sell them to me? For me, it's a win-win.