Advertising or marketing clutter refers to the large volume of advertising messages that the average consumer is exposed to on a daily basis.

One explanation, in a general sense, is that advertising clutter is often a result of a marketplace that is (over)-crowded with competing products. Heightened competition from this phenomenon has led to the emergence of other advertising strategies, including guerrilla marketing, viral marketing, and experiential marketing along with new focuses on humanising messaging within marketing.^{[citation needed]}

Studies have shown that annoyance factors from online advertising clutter is a significant contributor to advertising avoidance.^{[improper synthesis?]}