Ultimately, the most important thing you can do, is looking at each piece of your marketing plan and ask, “What was the real effectiveness of this activity?” If you don’t know, then set a metric for it. Force yourself to find ways to quantify success based on engagement or leads generated or best of all, the actual return on marketing investment (ROMI). Perform market research to gauge how impactful your marketing is. With offline advertising, try and force people to make a trackable action. Ask them to call a different number you can track separately. Send them to a vanity URL instead of the homepage of your website.
Then sit down and look at the figures and ask yourself, “Is it working?”
If the answer is no, then make changes to the messaging, targeting, etc. and try it again. Or take it off your plan and replace it with something else. If the answer is yes, then figure out if you can do more of it in different markets or with a different promotion/product/service.
So long as your marketing is generating a return and you’re managing the other aspects of your business wisely (including cash flow and deliverability of your product/service), you can continue to invest in marketing activities that work.
Stop asking how much you should be spending on marketing. Start asking “How much can I spend on activities that are creating results?”