When it comes to reaching would-be customers today, one of the biggest investments that brands and retailers will make is in advertising, to the tune of nearly $630 billion globally. Now, a startup called Dosh, which offers cash back on purchases, is announcing that it has raised $40 million to take on the advertising industry, with the pitch that its app provides a more targeted and guaranteed way of getting consumers to bite. The funding — $20 million in equity and $20 million in venture debt — is led by Goodwater Capital and Western Technology Investment.