AIDA is one of those acronyms that most marketing people can quote but that most forget to implement when they are writing copy.
A = Attention:
The all too brief few seconds you have to grab the prospect's attention. This is usually with a headline or an image that is relevant to the customers you want to attract. It should never be with a brash headline like, "free money" because as you try to move people into the next part of your advertisement they will lose interest.
I = Interest:
Having gained the attention of the right people you have a few more seconds to turn that passing attention into genuine interest. This will be easy because you will already have researched your target audience so you will be talking to their needs. Your interest section will typically only be a paragraph, you really don't have long to generate the interest that will keep them reading.
D = Desire:
The few people who have stayed with you this far are interested in what you have to offer. Your next job is to create a desire for your product. You will do this by relaying in more detail how you understand their needs and how your product is ideally suited to meeting those needs. You may want to show them how they will be better off after they have your product and it is working for them. You may want to explain why your company is the best one to provide this product and how well you will support them during and after their purchase. Desire is the bulk of your advert/web page, it is your main selling piece and must be backed by solid customer research to have any chance of working.
The last part is the most important and the part that so many people either don't do or do badly. If you have led people through your marketing piece and generated desire for your product then you really need that final A of AIDA.
A = Action:
Any marketing piece, web page or advertisement needs to include a call to action. Imagine walking around a department store with a basket full of thing you want to buy but there is no checkout. Sounds stupid and yet most web pages fall into that trap. Make it very clear what your prospect has to do to become a proud owner of what you are selling. The most effective call-to-action will be time limited.
A time-bound call-to-action drives more people to respond quickly. It can be a limited time price reduction or some additional add-on or enhancement during the first month. Whatever it is it has to be appealing to the prospect and of sufficient value to make them stop dithering and take action to buy your product.
Many people are scared of picking up a phone; if your call to action is to call you then you will have a lower response rate than if you drive them to a web page. If you use the web page, don't send them to your home page! Why? If all you advertising sends people to the same web page you will have no idea of which marketing pieces are working and which are not. Create dedicated pages for each advertisement so you can count exactly how many people respond to each activity.