Changing the World

Pros

• having an impact on the lives of millions of people feels great

Cons

• usually this means working for large multi-national companies since the small guys aren't big enough to work at that scale; this means your work is aggregated with hundreds of colleagues and therefore it's harder to get noticed for great achievements/performance.
• there is a lot of risk involved when trying to work on innovative things; either the company or yourself must cover the costs of potential failure.