Sync for Lemmy

You can interact with the post if you're signed up to Lemmy.ca, which the users I'm sharing the posts with are.

I can't interact with the post from lemmy.world's site if I don't have a lemmy.world account.

And realistically, you would only want to share content through your own instance, as it's the only instance you'd want to vouch for and can guarantee it is free of advertising, lewd UI themes (ahem, yiffit), bad redirects, or anything that could weird out someone visiting the content you're sharing with them. There's also the "you always send me links from random websites" factor, and people are rightfully hesitant to click on links from domains they've never seen before. If they know person X always shares posts federated to their own instance, they'll be more likely to trust the link.