I ran a Facebook a few months ago and collected over 3000 contacts. Then I stopped the ads, and now I am planning to run another ad with the goal of signing up more user and collect contacts. With the ad we are going to offer some deals, like Buy 6 Get 6. Can the contact who already signed up during the initial run enter the same email and/or phone number, take advantage of the coupon but still be one contact in my contacts list?

In short, can an existing contact enter her same email or phone number and get the new deal?