Many developers thinks that a pirated copy of their app means a lost sale.

Actually, it's not like that. People have various reasons for pirating an app, for example trying them just for fun.

In fact, in most cases, a very few people will do a very long search on the net to get a $1 application for free.

In my opinion, if an app has an high piracy/sales ratio, it means that for "honest" customers, the product does not offer the right appeal, and for pirates it's just a trial, that means, they still won't buy your $1 app - it's not a lost sale.

The perfect example it's Walk and Text for Android, an app for texting while walking: it just displays the camera on the screen while walking; nothing exceptional here. To be honest, I won't get such kind of useless app even if it's for free. So, "honest" people won't buy the app because they feel the uselessness; while compulsive pirates will download it just for showing to friends "hey, I can text and walk". If you watch it in another way, the pirate will spread the voice between friends. Every "heavy pirate" that I know, loves to show off the fact their hundreds of useless apps.

This means that, sometimes, piracy sometimes can lead to a sale.

But, if you act recklessly like the developer of Walk and Text for Android, that acts like a virus if cracking it's detected, you generate a lot of bad advertisement: "hey, that app will bill me $$$ if detects a crack, better avoid it like a skunk!

In this case, piracy really means a lost sale.