I would argue that "money spent on advertisement is money not spent on R&D and improving the product" isn't strictly true. Yes you can spend money in improving

I would argue that "money spent on advertisement is money not spent on R&D and improving the product" isn't strictly true. Yes you can spend money in improving the product instead of advertising. But if advertising increases your profit, then you have even more money to spend on r&d. It isn't exactly a zero sum game.