Obviously, dogPile doesn't submit a search to each of the search engines every time you enter something into dogPile. For one, that would be very foolish for speed (as your problem is showing). Surely dogPile saves the results it fetches from the engines and reuses that the next time someone else queries for the same search.

So for example, you search for 'hello world'. dogPile sees that these search terms haven't been fetched before, so dogPile queries all the search engines. Next time someone searches for 'hello world', dogPile doesn't need to refetch the search results since it cached them on its own servers.