Xianyu is basically another face of China's dark web, but the area where it truly makes money isn't in secondhand goods at all.

When you open Xianyu and bypass those pages selling old phones or transferring fitness memberships, and dig deeper, you'll see some shops with very strange titles: cross-province car transfer, assistance with renovation, quote review, resume issue diagnosis.
Prices are listed very low, service descriptions are very brief, and it looks like a few ordinary people doing odd jobs. But interestingly, under every comment below these reviews, the same kind of words appear: "So worry-free, I tried to handle it myself for a week and couldn't get it done, asking others is better than spending this little money."
This isn't a secondhand platform; it's a marketplace for代理 (agency services). I've observed for a while, and there's a group of people hiding inside—what they do, you could do too, but you just can't do it smoothly.
For example, you sell a car and transfer it across provinces. You go to the vehicle management office and are told you're missing a proof document. You go back and get it, then go again and are told the insurance hasn't been canceled. Cancel it and go again. This time, they say the original owner's information system doesn't match. Three weeks have passed, and the matter still isn't settled.
People who take these orders on Xianyu, you send them a picture of your driving license, and they tell you which day to go, what documents to bring, which window to go to, or even accompany you for half a day to run the errands.
If you're renovating a house, the renovation company gives you a quote, with detailed costs for water and electricity modifications, main materials, labor, etc. You can't see any issues.
There are renovation industry insiders on Xianyu who review these quotes. You send them the list, and they reply within half an hour with comments: how much is inflated in this item, what's missing in that one, what tricks this company usually uses.
You take this critique back to the renovation company, and they can't even speak smoothly.
If you're in your thirties and want to change jobs, you send out 100 resumes, and only get three responses. Do you think it's because you're not good enough?
People who review resumes on Xianyu tell you, it's not that you're not good enough; it's that your resume can't pass the system.
What keywords does the HR screening system look for? How should industry terms be written? How should project management be listed?
You don't know these, but they help you reassemble your resume. When you send it out again, interview invitations start coming in.
What do these three things have in common? It's not that you're lazy; it's that you don't have the right channels.
The vehicle management office handles thousands of transfers a year, but you might only do one or two in your life.
The renovation company's quoting scripts are practiced hundreds of times, but you get scammed once when you renovate your house.
The HR system's screening logic is written in the company's internal manual, and you'll never see it in your life.
The gap between you and them isn't money; it's information, experience.
They've done it a thousand times, and the one you're doing for the first time is vastly different.
And what those people on Xianyu do is openly price this gap.