Credit: Joanna Stern / ABC News

Facebook seems to have even more products up its sleeve. On the heels of releasing its new hashtag feature this week and the roll out of its new iPhone and Android features, the company will hold an event on Thursday, June 20 at its headquarters in Menlo Park, Calif. to show off a "new product."

"A small team has been working on a big idea," the invitation reads. "Join us for coffee and learn about a new product."

The event invitation was sent to reporters today, though not through the usual digital means. Nope, ABC News didn't receive the invite over email or even Facebook, but in a clean white envelope sent via snail mail. No, there wasn't a chat head stamp.

Facebook has announced a new hashtag feature. Read more about it here.

The mysterious invite is almost as mysterious as the upcoming event.

There have been few rumors about Facebook releasing major product updates over the past few weeks. Facebook did say earlier this week that it would be making additional announcements over the coming weeks about its public conversation features.

"We'll continue to roll out more features in the coming weeks and months, including trending hashtags and deeper insights, that help people discover more of the world's conversations," Facebook's Greg Lindley wrote on Facebook's blog this week. However, Facebook did not hold an event this week for the hashtag release.

Whatever it is that Facebook has up its sleeve, ABC News will be covering the event on June 20. In the meantime, tell us what you might want to see Facebook announce in the comments.