Adwords Pay Per Click Pays for Itself
If you invest for example £1000 and pay £1 for each click on your advert, this will result in 1000 visitors to your website who are actively looking for what you are offering.
If 10% of these visitors buy what you are selling you will make 100 sales.
If your average sale is £100, a £1000 initial investment will result in £10,000 of sales.
You can start off with as little as £1 to see how this model works.