I like the concept and I think your little cartoon is a good way to describe the premise. I would include a "recently searched items, or screenshot of a search on the home page. Something that would re-enforce that you are legit to outside people.
When I went to terms, press, etc.. I noticed that you are using the search layout to display the results. I initially thought this was a little strange. I then realized my expectation was to have a typical document experience not the same experience as a search.
Finally you mention that the profits go toward cancer research, but you don't mention which type of cancer or the fund you are donating the money to. I think having a link to how/where/when you are donating the profits would be a very good thing to have. Maybe even include a counter with the dollars donated.