Guest Commentary: We launched Zapd yesterday to great fanfare — hundreds of users were signing up each hour and posting their Zap’s to Facebook and Twitter (driving thousands of more users). The traffic was insane. It was a better first day response than our previous two companies (ImageKind and Inkd) … combined.

Why is this happening? Honestly I don’t know. There are lots of comparisons to Tumblr and Posterous. Maybe all the news about the launch of Colors last week. Maybe just bubble-level hysteria around mobile apps in general. I just don’t know.

Unfortunately, at 5 a.m. this morning the omni-present Facebook spam algorithm had enough of our success and shut us down: no more sign-up’s and no more wall posts for existing users.

We built it, they came, but Facebook pulled up the drawbridge. They don’t really tell you WHY they do these kinds of things. App developers are left guessing.

What’s interesting is how they are set up. You can only apply for a 48-hour appeal — unless you know someone. Facebook really seems to prioritize those developers who are “friends of friends” within Facebook.

We sent out a plea for help to our network and everyone out there seems to know how Facebook works and now we’ve got 10 different emails going in to various places throughout the Facebook organization. Stay tuned on that.

Fortunately, because others fell victim to this problem, we knew this could happen and so we built our app in a way that allowed us to quickly implement a workaround.

You only get one chance to launch, and so no matter what happened we had to be live. We were up and running a few hours later. In the mean time, our many friends and colleagues were helping us contact Facebook to expedite the appeal.

The most frustrating aspect of the experience is that the Facebook shutdown came without warning, without explanation, and with a ridiculously long waiting time to address the issues. Also, it was total.

We get that Facebook may need to shut down spam but why shut down sign-in’s and lock out an app completely!?! Was it because there were too many new users? Too many posts per user? Or something else? Facebook doesn’t tell you all that you need to know up front.

We’re still working on addressing this issue but here is what we’ve learned so far that we can share with anyone new to developing on Facebook.

Don’t launch without knowing somebody at Facebook first. Ask around. Get a name first. Build a relationship. Because otherwise Facebook is notoriously hard to contact. Don’t rely solely on Facebook Connect to set up user accounts. We wanted to keep things simple and so we offered Facebook and our own system and although it made things easy it also increased the impact of the Facebook ban. We’re working hard on adding Twitter and Google logins to avoid this problem in the future. Don’t blindly rely on the Facebook SDK. You’re literally handing the keys to your app to Facebook and your at their mercy. The code is open so read it, understand it, make it your own.

Have more experience developing for Facebook? Share it with the entire Seattle tech community, so we all benefit!

Kelly Smith is founder of Zapd, a free iPhone application that allows users to create Web sites from their mobile phones. [Editor’s note: Smith also is the founder of Inkd, which is one of GeekWire’s partners].