Marketing spend for a B2C companies should be a minimum of 6% of annual sales. For B2B companies, 3%. Do the calculation and divide by 12 to get know how much you should spend per month. This varies across market segments, with premium products and services allocating much higher marketing spend. Spending the absolute minimum on marketing always erodes competitivity. Prioritize which marketing initiatives creates the most impact impact for the least money. In other words, track return on marketing investment (ROMI).