Inherently, the whole business of advertising is based on consumer trust. Without it, not a single advertising campaign, no matter how elaborate or expensive, would have a positive effect on consumer decisions or brand identification. It is therefore very much in the interest of the advertising industry not to break consumer trust.
That is why the European Advertising Standards Alliance, together with its network of national self-regulatory organisations and advertising industry associations, promotes best practice to keep advertising:
Start tour here -> 3 good reasons for self-regulation