My guesses are:

1) Maybe Viglink offered a deal to get exposure. I never heard of them until today.

2) They claim to cover 30k merchants.[1] Maybe there is a lot of money for reddit in the 29,999 other sellers too.

[1] https://en.wikipedia.org/wiki/VigLink

Vigilink also offers a great short term solution to help them get this out the door, and figure out how much they can make. In the future, they can do the math, and pretty easily decide if it's worth taking the time to rewrite the urls / manage a bunch of affiliate programs themselves to increase their margin.

VigLink's value to Reddit is likely in the ability to tag a very long tail of non-Amazon merchants.

Rewriting links for dozens, or even hundreds, of networks is trivial, it's just just a bunch of regexes. Creating dozens of affiliate accounts and managing them is the actual annoying part.

Weird. Also, Amazon links are not part of the program: https://www.reddit.com/r/changelog/comments/4ldk0r/reddit_ch...

It's a maintenance nightmare. And using services like viglink your code only deals with a single provider, like you say, you add a single tag and it works with plenty of metchants.

Potentially this also opens for other use cases such as substituting the product name with a link to buy, maybe useful in some specific subreddits.