> EDIT: it’s possible you might be preempting the downweight because you’re including a screenshot with all of your links. I.e. the downweight only happens if twitter shows the expando for an external link, which doesn’t happen when screenshots are included. Either way, I’ll be implementing your technique. :)

Interesting. The reason I've always done this is just because I want to give people a meaningful preview of the first few paragraphs. And I figured that it's been effective. In more than one ways, perhaps, now I see.