If you look at the numbers, after the beta Imgur was starting to grow again. It was a hit yes, but not an exodus.
Well… sure, you could say at first it was more of a symbiotic relationship, though probably providing more benefit to reddit than to Imgur, the latter absorbing the former's bandwidth costs and not getting much in return.
The parasitical part comes with
> but now Imgur has its own community
because, in order to ensure its survival, Imgur has tried to grow itself into an independent community on the back of reddit, to eventually be self-sustaining.
Now that reddit's cutting it off, maybe it actually will be self-sustaining. All the more power to them if that works.
But I don't think “parasitical” is an unfair characterisation of how things have worked so far. It's not really intended as a value judgement on my part.
It was absolutely a parasite. It would not have survived to grow to the size it did without Reddit. Parasites can offer a beneficial service to the host but cannot live without it.
It has since evolved into something possibly capable of existing on its own but only time will tell.
My guess is it lives for a few more years at best.
Incidentally, this is not what biologists consider parasitism. To a biologist, a parasitic relationship is one that benefits one while harming the other. Do you think that reddit was harmed by imgur? If imgur benefited but reddit was not harmed, their relationship was commensal. If they both benefited, their relationship was mutual.
To capture the idea that imgur was totally dependent on its relationship with reddit (but not vice versa), you would say that their mutualism was obligate for imgur but facultative for reddit.
Parasitism is when one party benefits while the other is harmed.
It's true that Imgur has to grow its product now to something bigger. I won't even give them many years if they don't do that for a product that simple and ephemeral. They have challenges here.
The parasite metaphor does not include the idea of being a "copy-cat"; parasites in the real world do not do the same things as their host. Indeed, that is the entire point of a parasite, in some sense; to take advantage of the host setting up various expensive systems to survive and just using them instead of developing their own.