I can't give specific numbers but partners are currently a very small portion of our traffic.

http://screencast.com/t/yZIkmNkMV8wp ^ Fresh Opera install. Opera ships with DDG but not as the default. Frankly I would guess that the impact this has is insignificant: Opera has a small user base in the first place, and ddg is just one of several options in a list. How many people will, without prompting, explore what this new search is in their Opera, and understand the benefit of using it? At first blush (without knowledge of the privacy protections, bang syntax etc.) DDG is just a cleaner, slower, unfamiliar google with worse results. (I say this as someone with DDG as his default on all browsers.)