Email Marketing Part I

This is my journey on email marketing, my target is to build my own email list. My target is 100 emails and monetize those list. See the following numbers:
-PPC cost / click = $0.05
-PPC CTR = 20%
-So to get 100 emails, it will cost me = 100 * (0.05 / 0.2) = $25

So I need to find a product which I could get $25 for 1 sale. Consider I have 1% sales conversion from the 100 emails.