I have a question about Geo Targeting. I think that it is a great idea, and would like to implement it as many of my visitors come from Europe and Asia as well as North America and it is great that advertisers can select their regions for these viewers.

I have set the option to continents. Some of my advertisers may want to advertise globally. Do they need to purchase a package for each Continent? Is there any way to offer a discount if they choose more than one Continent?

Hi,
They don't need to purchase a package for each continent. So, you don't have to offer any discount.
Best regards,

Soooo..

If they want to advertise globally, they just pick no Continent? And if so, what is the advantage of offering Geo Targeting to clients? How does it benefit them, if they don't get a discount. Do I add a package at a different price for those who want to choose just the one?

If they purchase 1000 impressions for a specific continent they will be sure that all these impressions will show only for people living in that continent. This is the main advantage.
Ex.
You have a business on United States and you pay $10 for 100 impressions. But you show that ad globally. In this case you are losing money because a lot of these impressions could be shown on europe or asia or other continent.
If you offer geotargeting, you will be able to pay $10 for 100 impressions only for United States visitors.
Best regards,