As you have likely already surmised, most advertisements today are rendered ineffective: the people who see them either aren't interested in what is being sold or they're simply not part of the early adopter segment who are open to new solutions and will to spread the word about them.

Now you may ask: What's so special about the advertisements that DO work? How can you tell if yours do?

The definitive key is to target your advertisements effectively.

This is because, earlier marketers could choose whom they wanted to reach, nowadays the sheer abundance of advertising means it is the customer who will have to choose to listen to you.

This means that your advertisement has to target the right people looking for a solution - your solution - to their problems. This is achieved by putting your ad in a place where they are looking for it.

Let's take Google Adwords for example, it works well in this respect because people type in their search terms that reflect what they are specifically looking for and the ads that display are selected to offer a solution to whatever problem they are looking to solve.

No matter how you advertise your product, you will still need to measure the effectiveness of your marketing efforts. This is the only way in which you can decipher what works and what does not work so that you can optimize your actions and conserve money and energy.

As an example, the clothes retailer Zara keeps a close eye on how its products are received in stores and out in the world, they adjust the selection of clothes every three or four weeks according to what they find out.

Remember, you can only optimize campaigns that you can measure, so in addition to thinking about how effective an action is, you should also always consider how much it will cost to measure.