Typical - sites like this relies on affiliates to grow their presence and then gives that kind of "thanks".
That being said - you always want to have your own domain/site and link to it. Not have your aff links on sites that may one day cut you like that. It has been proven time and time again.
I wouldn't say Pinterest ever relied on affiliates to do much for their presence. It's always been driven primarily by women who like to shop and craft and post cheesy quote pictures and read articles about how to make toddlers behave. There was shockingly little affiliate activity on there for ages, then there was a brief surge in Amazon affiliates for a while that they
squashed pretty quickly. Everybody got mad and said affiliate links had been killed, but it was really just Amazon, and that was enough to get rid of the worst of the spam.
Fast forward a couple years, and some companies sprang up to take advantage of the whole social shopping concept - basically making it easy for non-technical types to become affiliates. Members-only flash sale sites like One Kings Lane did the same, adding unique referral IDs to social shares and giving people credits instead of cash for their sales. As would be expected, people with lots of followers got greedy and started spamming everybody with nothing but their affiliate links.
So...now they've shut down the networks that make it really easy to be an affiliate. As of today, my Pinterest accounts still have plenty of functioning direct affiliate links from programs that aren't Amazon or RewardStyle. Granted, I still do a lot on my own sites because I don't like my income to be totally vulnerable like that - but given the low hourly wages I pay my helpers in IL (who do a great job of keeping it all very real), it's still worth it to me to have a lot of direct links. I just avoid the few really popular programs since that's where the abuse generally occurs.
Every time I see them shutting down more affiliate links, though, I have to laugh. I met Ben Silbermann at an event in Palo Alto a few years back, and one of the guys chatting afterwards asked him about affiliate links and what they intended to do about people spamming the site with them. Silbermann said something to the effect of, "We don't need to do anything - our algorithm is such that if you don't want to see links about affiliate marketing, you won't see affiliate things. Affiliate links will never be a problem." I'm not convinced he even knew what an affiliate link was at that point in time (though someone on their team must have known, since they shut down Amazon links shortly after).
There's still plenty of money to be made with affiliate marketing + Pinterest.
