Did you realise how many adverts people see every day? In the 'developed' world it's somewhere between 2,000 and 10,000. The biggest battle you have in promoting your business is GETTING THE ATTENTION of your future customers.
Other people will tell you about how you have to be everywhere on mobile devices, billboards, on TV and radio. But as you already know if it's not the right message then you're just burning money.