> Paypal famously got to scale by becoming the currency of choice for eBay buyers and sellers.
Slightly off topic but after seeing this statement, it triggered an old question in my mind: would anyone happen to remember how payment-industry companies like Paypal were able to scale so well when their model depends on traditional ACID properties? I've never been in the payments field, but I've always wondered how their backend structure differs from those of say Netflix or Facebook, of which I'm more familiar with.
Transactional logs. It's like double-entry accounting. You build the state by keeping each transaction and then processing them in order. You can obviously cache at intervals. This allows for a full audit trail. Bitcoin is also a sum of a complete series of transactions.
The interesting part is how they got any users. Even a junior programmer could build such a system within a day. The answer is: Give each new users 10$ then an extra 10$ for each user they recruit.
Acquiring users in this field is the hard part.
Slightly off topic but after seeing this statement, it triggered an old question in my mind: would anyone happen to remember how payment-industry companies like Paypal were able to scale so well when their model depends on traditional ACID properties? I've never been in the payments field, but I've always wondered how their backend structure differs from those of say Netflix or Facebook, of which I'm more familiar with.