Best way to make money on the side

With as little ongoing effort as possible. So far I have a few ideas:

- Click fraud
- Games on mobile app stores (Android, iOS, Win8)
- Web apps with advertisements and premium subscriptions
- Botnet that executes a bitcoin miner

>>1
- Click fraud
Very little money to be made

- Games on mobile app stores (Android, iOS, Win8)
You aren't a good enough programmer to make anything that anyone would pay for

- Web apps with advertisements and premium subscriptions
You aren't a good enough programmer to make anything that anyone would pay to advertise in

- Botnet that executes a bitcoin miner
This already exists in several forms.  There is a web script that will do it, so that anyone viewing your web page is unknowingly mining coins for you.  Or, more directly, you can just set up any of the existing miner programs to operate in network mode.  I guess that's not technically a "botnet."  But the difficulty level of bitcoins is far too high now for anyone to ever make money mining again.