Altavista, Hotbot, Ask Jeeves, do we really need another search engine? Why do you think Google will be better than Altavista?
my personal opinion is that search, which sates the quest for information, is a problem worth solving. chat, at least as the text-based instant message kind of things, creates problems. or rather, it's an opportunity loss.
the fact that i'm talking means i'm not listening. even if this weren't procrastination, even if my main goal in life was to communicate with strangers better, is IM helping me get there? is this the problem olark wants to solve, or do they just want to make yet another IM service?
(ps - i think visually. i communicate best with diagrams. discussions with my husband require a whiteboard or paper scrap. i'd love a communication company whose mission was to prevent misunderstandings. make exchanging perspectives faster, help us get along and respect each other while disagreeing, help us make decisions better.)
When evaluating an opportunity, "___ is a competitive/crowded space", "___ has already won this market", or "does the world need another ___" are all valid objections to raise. The rebuttal should be "but ___ is better/different because of ___" rather than a comparison to Google.