I very much doubt that Dropbox's target group are users with bandwidth limitations. Yes, it's nice to have features that minimize waste on the network link, but

I very much doubt that Dropbox's target group are users with bandwidth limitations. Yes, it's nice to have features that minimize waste on the network link, but I'd bet far more people would trade that away in exchange for laptop battery life and a smaller hit on their CPU. If they're only targeting that niche, then they have a business model problem. Make it an option ("Minimize bandwidth or battery usage?")