I’ll just say this: If the ads you use pop up as soon as readers visit your site — forcing them to find an “X” button to get rid of the pop-up and get onto what they’d hoped to read on your site, it’ll turn them off. I absolutely cannot stand a website that does that, and I’ll go to great lengths to avoid ever going onto any site that has pop-up ads.
Basic rule of thumb: if they’re hard on the eyes, readers will be turned off. I even find the ads placed at the very top of our blogs here at blog job to be a bit distracting and they take away from the post.
Just as long as you aren’t over zealous with placement (meaning keep the ads from totally taking away from your content and try to aim towards making the ads and the content work together), you should do just fine. 😉