Jeff contacted me after I launched. We are in the middle of a conversation about this, but we both had to go to dinner (he with a group, and I hadn't eaten all day).

His concerns are valid, but we are both wanting to finish our discussion (it is/was quite open).

However, the canonical answer to "why do we need another X in this space" is "why did google need to be another search engine?" It may be that we are fulfilling different demands, and we both agree that competition is better for everyone involved.