Riddle: If there are 5 frogs on a log and one decides to jump, how many froms are left?
Answer: 5 frogs. The frog only decided to jump but did not actually take action. There is a huge difference in a person intending to buy a product and actually driving to the store and buying it. While purchase intent in a good metric to consider a much more concrete measure is actual increase in purchase behavior. It is also important to make it as easy as possible for someone who intends to purchase your product to act. For example Amazon's 1 Click or Starbuck's drive-through or iPod vending machines.