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captainhcgon Ask HN: How does Facebook know what I buy on Amazon or vice versa?

I am working at FB but not in ads or related team. But I had talked to a person who is directly working on it.

Amazon is different to other AD buyers. Amazon does not want FB to know what customers are doing on its own site, so there is no FB tracker on Amazon at all. However, Amazon can choose what ad to deliver to you on FB backed up by its own team.

captainhcgon On Growing: Lessons from the Story of WeChat

- `How does the money enter the network in the first place? You can use services like Venmo without linking payment information, but obviously you can't withdraw your balance. reply` - `So where is that e-money coming from? You must be linking something... a bank account perhaps?`

Nowadays most people have already linked their accounts with bank. But you still do not have to. When the feature first released in 2014, most people used the e-money for social purposes like sending gift cards and transferring small amount of cash; people just did not withdraw money.

That's one of the most important reasons why WeChat won tens of millions e-money users in a very short period.

captainhcgon On Growing: Lessons from the Story of WeChat

`You can send or receive money in Messenger (example: send your friend $10 for lunch or receive $500 from your roommate for rent) after you add a debit card issued by a US bank to your account.`

It requires you to bind your account with a debit card. I am using WeChat for years but I never attach my debit card to it, because I do not have a China debit card. When I need e-money, I just ask my family or give my friends some cash and they transfer e-money to me. That's all. Then I can use the e-money for offline shopping, online shopping, sending Hongbao (as gift-card). I do not understand why debit card is required.

captainhcgon Google Ends Page Speed Service

This was an amazing product to me one year ago. I used it as CDN for my blog hosted Amazon EC2; it speeded up the visits a lot across the world.

However, I stopped using it last year since China blocked all Google service while my blog is mostly for Chinese readers. Though the proxy/cdn service is shutting down, the Pagespeed Module of Apache/Nginx is awesome, which is what I am using right now.