Imagine that a product exists, maybe a tool, maybe an entertainment product, that is just perfect for you. It's the thing you didn't realise you'd been waiting your whole life for. But you don't know about it.
In an ideal version of reality, how do you want the sellers of this product to let you know that it exists and you can buy one?
I guess the flip side to this question is; how do you ever know someone wants to hear what you have to say? Isn't society one big collection of unsolicited messages?
Do the ants in the grass understand what the man's Volvo is?
Do they know you can buy Pepsi in aluminum or glass?
Advertising is art with an ulterior motive for existing. As long as we're not being openly lied to, I don't think it's bad exactly, but in a world where there are important things to do, I would suggest it's probably doing more harm than good.