Media buying: Banner blindness
I'm going into banner ads and I had hoped that they would be 'set and forget' once I've optimized them, at least for a month or two, but I've heard that banner blindness can set in within as little as 48 hours, which is something I thought only occurred at places like FB, POF etc. What's the average time it takes for banner blindness to set in and what are some factors that can contribute to it, e.g. website size, image type etc.?