Don’t be a bad ad.
If you are trying to balance the need to be noticed with the need to make friends, see The Most Hated Online Advertising Techniques, from Neilsen-Norman Group, one of the most respected user experience research firms. Their research confirms what most of us already know: that users hate, hate, hate ads that obscure or rearrange content, are hard to dismiss, or play sound or video automatically.
If making your prospects hate you is not sufficient incentive to be a good guy, Google and Bing are increasingly penalizing sites with obstrusive ads, pop-ups, and interstitials, especially on mobile.
This is not to say all ads are a problem. Be aware of the tradeoff between getting the attention you need and irritating your prospects in the first moments of the relationship. Modal ads (as in the illustration here) are bad; those that cover the whole screen and make you search for the close link are cruel; and on mobile, anything bad becomes downright evil.