I recently registered as a user on Twitch, and was surprised by the amount of dark patterns there. It seems like every other action costs money, which isn't necessarily bad, but it makes me wary of clicking on anything because it seems half of them lead to a payment screen. It's just that there's no indication of what's a premium feature and what's not, and that's clearly intended to get users to want to perform an action and emphasizes what they're missing out on.