Most startups I consult for (growth/biz dev) are doomed because of their ignorant views on marketing (vague term, but I’ll use it as a catch-all). The bar is so low to start a business right now that you have a ton of really skilled engineers building things because they can, without nearly enough thought into how they’ll get customers and partners, never mind retaining them. I can’t tell you how many times a founding team makes a product and then looks for a “marketing guy” with the cliched If you build it, they will come assumption. “I figure you’ll need maybe 10% or 20% of your time to get us from 0 to 30,000 users” – this was actually said to me by a CEO with a straight face.
Marketing involves strategy and planning and measuring and tweaking and monitoring and negotiations and relationships. Give this function (and its many moving parts) its just due or suffer from it.