Money can corrupt, but so can poverty.

There is a financial sweet spot where the contributors to DuckDuckGo are fat and happy and there aren't greedy investors wanting to monetize all that trust.

Google has already occupied the greedy investor niche. DDG has carved out a niche where, I fear, the greatest threat is a lack of money for the people building and maintaining DDG. If they feel underappreciated, they may start to monetize that trust. The DDG team should be rewarded for their hard work.

No concern here. While we don't disclose the figure our CEO has publicly noted that we are indeed profitable:

http://fortune.com/2015/10/09/duckduckgo-profitable/

A quick Google search indicates that they've taken on ~$3M in funding. Depending on their revenues & expenses, that may mean that their investors aren't clamoring for quick returns. But at some point most investors do want to see a ROI/exit.

Not if it's a vanity investment (I don't know if there's a better term for it). If some VCs know that their fund will ride on one or two unicorns (or network effects like in YC's case) and that the rest of the investments will fail or barrly return 1-5x, once it's clear what the unicorn is there's a little room for investments that aren't expected to have a financial ROI. Perhaps the investment gets the investors a foot in the door for future ventures by the team or into a field where they might not have deal flow, or they might just want the extra "street cred" and publicity. YC regularly gives slots with funding to nonprofits now, which by definition can't have a financial ROI.

Because they've taken VC money. Usually, even if a business becomes profitable investors do not want to wait out a long term approach or be involved in a "lifestyle" business.

we (USV) are the VCs who invested in DDG. we are very patient. and are happy to wait and see where this goes. this was a very small investment for us so there is no pressure on them from us.

Great to hear. Just shows not all money is equal. People remember these things.