This is probably one among the most cliched discussions but more often than not people just escape it either by talking in favor of it or against it. If someone seriously thinks that ideas are not worth a dime, then that idea should be out in public without any fear of being copied.
I personally think that ideas are more than a dime, unless it's an outright clone. And I am not saying it because of the fear of being cloned or copied; I am rather saying it because discovering/inventing a useful idea is so rare. So it's the scarcity which makes it valuable and not the fact that someone might steal it.
EDIT: Important point missed. The discussion applies more to the people who can implement their ideas on their own.
2/ Offer free salary calculations. Charge employers for sending paper salary slips (PDF versions are for free) and employment related and legal counseling. Also offer free self-service portal for employers and employees. Barrier: requires a lot of knowledge of local employment, fiscal and social security regulations. Reward: if you can break the barrier you'll probably be the first and make a killing.
3/ Offer a service like square with the distinction that once a cent is converted to a online cent the entire history of that cent's online usage is freely accessible (radical transparency.) As soon as the cent is withdrawn that history will be lost of at least will be frozen for ever. This way when I want to accept a payment from you I - or my application - can scrutinize the history of the cents you offer me. If there's something in the history of a certain cent that I don't like - example: it's been used to buy X, Y or Z - I'll reject that cent. Other people can step in and tag transactions or even a party in a transaction in a certain way so that I can configure my application to reject those tags. This simple mechanism introduces a new negative feedback loop in our economy that we don't have but need in our economic system.