That's fine, Piyush. So in terms of the user experience, we have many measures, actually. But on the ones -- for your easy understanding, that we see user expansion, first of all, is word of mouth. Besides our marketing activities, there is also word of mouth and, more importantly, is the user retention and also user spending and also users' time spent on our platform and also cross-platform time spending by the users. So there are many ways.
And the other matters you might be interested is the conversion, right? It's how many just users convert into buyers and then the buyer convert into the repeated buyers. So -- and then the loyal customers, where we have 88 VIP members on our platform who actually, spending level's very high. So this is what we're very happy to see.
And in terms of our spending, and why we used aggressively -- I think, okay, this is a question, very interesting. I thought about this. If we say we're very disciplined in spending, right, some people may be worried about you might lose -- you might give more room to the competitors because they're spending very aggressively and you're emphasizing on discipline. But if we're talking about aggressive spending, then other group of people are worried about how this is going to impact your profit margin, et cetera. So actually, this is a game that we play every day. It's a decision we need to make every day. So this -- we're -- first of all, when you look at our strong profit growth that gives us the bullets as well to fight. So we do have a very strong profit and cash flow to invest.
And secondly, while in the past several quarters, you've seen the efficiency out of our platform, when you look at the market spending as a percentage of revenue, when you look at SG&A and when you look at all of this spending as a total revenue, we have very good control on the spending. And we measure ROIs at very different levels.
So I think today, we still see the potential in so many areas. And we do believe we have -- we are the ones that have the best -- in the best position to extend our service across all of these areas in commerce and to help merchants and consumers. So I think it's -- we're in a good position to spend.
Aggressively, I think we have said that several times like in the past year when we expand our -- when we investment in our cost business, we talk about aggressive spending. When we invest into our B2C business, we always talk about aggressive spending. The key thing is that we spend aggressively, but the return should be ensured. So that's our thinking on that.