Sure, but it's also nowhere near the price of a private tutor. Regardless of subject, I don't think giving each student their own human private tutor is feasibl

Sure, but it's also nowhere near the price of a private tutor. Regardless of subject, I don't think giving each student their own human private tutor is feasible. I've become convinced interactive, adaptive, software based learning is the next best thing, at least when done right. For language specifically, the only way you're ever going to get anywhere close to the level of a native speaker is by actually conversing with native speakers. I'm still just starting out with Duolingo, but my plan is to finish the course I'm in (or at least get a decent way into it), then switch to Tandem or some other service that lets you trade lessons with native speakers of another language.