Advertising has been around for decades. It has been used by business to alert consumers of the products and serves they offer. If there is a ban on advertising, many business will need to find alternate ways to get to the consumers. If they are unable to do so, they will lose a lot of income and in turn, the economy will suffer since these businesses will no longer be able to funnel money into the economy.
No, bans on advertising do, in fact, lead to unforeseen consequences. When a blanket ban such as advertising is made, there is little way to predict what all consequences may occur. There are too many variables to consider to be able to accurately predict all consequences, thus some are unforeseen.