MediaPost: Burst Measures The Cost of Clutter
A recent study by BURST Media finds 57.6% think less of an advertiser that advertises on a crowded web page. That figure rises with income. Two thirds of respondents with income over $50K have a distaste for advertisers on a cluttered page.
The level of distaste and lack of tolerance for clutter also rises with age. Of those over 55, 50% say they will tolerate only one ad on a page. Not that they have much choice but this is good directional information in choosing a site to reach this specific demo.