I believe it is ethical to target the uninformed consumer. Let me state up front that this does not mean targeting such consumers with lies; dishonesty is unethical. What it means that whether a consumer is informed or not is not relevant to the role of the marketer, for a couple of important reasons. The first is that it is beyond the scope of the marketer to understand for certain whether someone is informed or not. To determine the ethics of a marketing action based on whether nor that action targets the informed necessarily relies on knowing the target's level of knowledge. In the vast majority of cases, one simply cannot know, and the cost to ascertain such level of knowledge would make the act of marketing cost prohibitive. In the real world, all the marketer can do is to target the target market, and maintain honesty and integrity with the messaging. If anything,...

Certainly, the sales person does, in ascertaining the needs of the target and then informing the target about the merits of the product or service being sold. The consumer still retains the right to judge for himself or herself whether the product solves his/her problems.
The second reason is that in a democracy, the state of ignorance is one in which someone should not exist. It is the duty of the citizen to be informed and educated. While there are sometimes barriers to educating oneself, the reality is that these barriers are usually low for most products or services. The citizen has a duty to be informed; this is part of the social contract all citizens have as voters. Being ignorant when performing the duties of an adult, including being a consumer. If you choose to remain uninformed, and…