Hey, it's Derek speaking. Thanks for the question. There're sort of two components there, I'll take them in reverse order. The first one is just about the ARPU gap, and what gap are we trying to close. I think when we think about our ARPU opportunity near-term and longer term, we're really looking at the audience we have, the engagement we have, the ad products that we have today, and the yields that we see in the marketplace for the inventory that we have, and what we're really excited about is the opportunity to just continue to drive demand into our ecosystem and get market-based eCPMs and yields for the inventory in the audience that we have. So, we're trying to drive towards that, and of course, we look at peers in the marketplace near-term like a Twitter, which we think is a benchmark we want to drive towards, and obviously, we've got opportunity to go beyond that, and that's where we get into some of the discussion about how excited we are about the improving engagement on the user side. We pointed in some of the prepared remarks and highlights for the growth that we're seeing in engagement on Discover, with the time spent being up there growing and engagement with Premium Shows, and in general the health of the ecosystem, and of course, when we see the growth in our DAUs accelerating year-over-year versus prior quarter, all of that just adds to our opportunity. And so, when we think about closing the gap, that's the kind of stuff we're looking at, and then to your other question, which is how much of the ARPU growth is being driven by usage, versus, say, optimization, and I think at this point, because we're not supply-constrained, we're looking at predominantly just trying to build absolute demand into the ecosystem. And so, what you see when we're able to improve our optimization and serve the right ad to the right user at the right moment, and we can bring more diversity of advertisers into the ecosystem, that just allows us to use our inventory more efficiently and it takes some of the pressure off yields, which is great for our advertising customers who would benefit from really low yields in ecosystem today, because we're not supply-constrained. So, that's how we see the marketplace yielding out, and hopefully that gives a little bit more color to your question there.