Dropbox referrals: as far as I know Dropbox has been one of the earliest heavy users of great referral bonuses. Let’s take another look. Here’s a view of all the (official) ways to top up your account, on top you can upgrade right away.

Customer retention: Dropbox (@dropbox) forces the user to choose a reason for their leaving and offering some help depending on what reasons they’re giving.

Launch marketing doesn’t have to be hard. Watch and learn from the Dropbox launch where Drew Houston posted a video to HackerNews filled with fun little details. How many can you find?

Humor: Dropbox tries a humorous approach when things take a bit longer as expected/or wished.

Via Matthew Gabriel Hudson.

Easter egg: If you rename a Dropbox (@dropbox) folder from “albert didn’t know” to “neither did aston” and then to “but rajiv totally knew! oh shoot!” there’s a little surprise waiting (OS X only?).

Via Dropbox forum.

Url Hack: Dropbox (@dropbox) uses the obvious url to make downloads for their latest software accessible on http://dropbox.com/download. It will automatically start to download the latest version of dropbox for your OS. Way to handle your customers.

Via @mecredis.