That means if you charged $1,000 for a product or service (like an SEO package to offline businesses, etc) you would only need to sell it to one thousand customers to generate one million dollars.
If your product or service was $500, you'd have to sell two thousand. That doesn't seem like many does it?
There are over 100,000 people on this forum alone that are all potential customers as long as you offer a product or service of value that actually lives up to its claims.
If you promote a product from Clickbank as an affiliate that pays around $30 commission per sale, you'd have to sell 33,333 units to make a cool million dollars.
How far are you from making a million? Do you think you have what it takes to make it?