I kind of think you're countering yourself here. Just like only showing relevant news is an interesting challenge, so is only showing relevant ads. Advertiser

I kind of think you're countering yourself here. Just like only showing relevant news is an interesting challenge, so is only showing relevant ads. Advertisers don't want to show you ads you're not interested in; they want to show you ads you'll actually find useful. In many ways, that's a much more interesting challenge than showing relevant news. Extending the advertising example, it's also a very interesting challenge to show people that highly-targeted ads can be a good thing. Just like it's an interesting challenge to convince advertisers to use your ad platform. Although they are not technical challenges, they are very interesting business challenges.