If an ad isn't blocked, I fast forward through it. If I can't fast forward, I mute it. If I can't mute it, I'll mute my computer and change tabs for the duration. If it's a page in a magazine, I flip it quickly. If it's a billboard I'll avert my gaze. If it's in an airplane I take out my headphones and cover the screen.
I find being advertised to so annoying there's no way in hell I will spend my limited time on this planet willingly consuming an ad.