It depends on the policy or situation of the site. However, your link can be for a minimum of one year, two years, three years, or a lifetime.
As for traffic, it depends on the website's traffic, the total number of visitors visiting the source website, and how well your article is visible or ranked on Google. So, we cannot predict exactly. But whichever platform you choose, you'll need to add some extra functionality, like social media engagement. Thus helping to increase organic and referral traffic to your website.