YES. This is a daft mistake if you don't - Ad buyers want to see impressions and placements before they buy. You need to determine their value. So if you want t

YES. This is a daft mistake if you don't - Ad buyers want to see impressions and placements before they buy. You need to determine their value. So if you want to sell ads, you need to have ads. If you don't like adsense, make house ads. Even if they don't earn anything you need to see which ad products perform best. Designers hate ads. Developers hate ads. They're ugly, they get in the way, they don't match, you need to install cumbersome systems to manage them, they create performance problems. But if they're a part of the business model then you better get used to them whether you like it or not. And no, users really don't care as much as you think they do. They only care if you put them awkwardly in places they weren't designed to go...