This is basically counterproductive. The problem with consumerism is buying things you would not otherwise buy (because you don't need or want them really). But obviously there are things that you do need/want, and if those things can be purchased on sale, failing to do so merely results in paying more money to the people driving consumerism.
If you want to protest consumerism (as I do), I suggest three methods of doing so which are actually effective:
1. Mindfully reduce what objects you own and what objects you take in. Read The Last Viridian Note [1] for a potential strategy for categorizing what objects belong in your life and don't.
2. When you mindfully conclude that you do, in fact, need/want something, exhaust all avenues for obtaining it for free, used, or locally, in that order, before buying from a retailer connected to the global supply chain.
3. Don't view ads. The entire raison d'être of capitalism is to provide the highest quality goods and services for the lowest cost. Advertising fundamentally breaks this premise because it allows lower quality goods and services at a higher cost to outcompete higher quality goods and services at a lower cost. Every dollar a company spends on advertising is a) not spent on creating a quality product and b) passed on to the consumer in the form of cost. More relevant-ly, advertising makes it much more difficult to mindfully reduce what you own and take in. No one is immune to advertising: modern manipulation tactics are more sophisticated than any of us can truly guard our psyches from: the only solution is abstinence.
[1] https://www.viridiandesign.org/notes/451-500/the_last_viridi...