I doubt you'll see this since the thread is old, but you aren't making a valid comparison.
You could not have realistically have 300k wives at the same time, but you could have 300k customers.
What you're saying goes completely against any type of advertising or promotional model that I am aware of. This is why there is more than just Cost Per Acquisition ad models.
If you get 30,000, you retain 3000, which could potentially be the 3000 that you need to gain traction and start gaining new users organically.