Any advertisement that does its job effectively will attract reader attention, often from a mass of nearby advertisements.  Often it is the headline or a well-placed graphic that accomplishes the task of arousing attention.  Interest is also created by the headline, but interest must also be maintained and if possible increased by words used in the text.   
Desire is created primarily by words and phrases used.  Play to man's basic instincts; show how your product or service can fulfil the reader's needs and ambitions, and a sale is virtually certain.  Which brings us to the action component of the AIDA formula. 

Getting the reader to act is accomplished by a variety of techniques including: making the job easy by offering credit card facilities, giving a guarantee, and perhaps including a telephone number for more sceptical readers to use. 

Writing Winning Headlines For Your Classified Ads.

You can have the most wonderful goods to offer, even unique goods with unlimited demand.  Your prices might be low enough to attract millions of customers worldwide and mean very good profits for you.  You might have goods customers will buy time and time again; goods they will recommend friends, relatives and acquaintances to buy - from you.  But one thing above all others is certain; if you don't advertise your goods, you won't sell them.  Stating the obvious? 

Well, yes, perhaps it is, and yet the fact remains that ineffective advertising is the one main factor in determining the downfall of otherwise superbly profitable ventures.  That is a fact!  Not recessions; not changes in consumer patterns; not rises and falls in the value of the pound against this or that other currency.  None of these things. 

Advertising is the one thing you have to get right to succeed.  Success depends on continuous effective advertising, which in itself means producing, analysing and continuously testing your advertising copy; reviewing it as times, consumer tastes, markets and other factors change, and more.  It also means looking for hundreds, even thousands of bulletin boards to carry your ads.

Read More about AIDA HERE