I think it will have impacts, these days the power or images are very useful (i think since from the beginning of trading goods and services). In advertising, colorful signatures and designs to promote sites and other business are likely to be clicked than a dull with old style ones. If you compare it to the real world, there are lots of shops out the street selling goods, some have their banners and ads hanging on their front shop with colorful writings and others crafts. Also how could anyone know you are selling such things if you don't tell it to the people? Everyday millions of users search this forum and there should be people who have seen our signatures.