Kara-mail (空メール) is a user interface design pattern commonly seen in Japanese mobile web sites. As all Japanese mobile phones have an email address, registration for mobile sites usually requires an email address. However, entering an email address is relatively time consuming for a user to do. So instead of asking the user to input the email address, sites have a user send them an empty email, hence the name kara-mail (kara is Japanese for empty). After the site receives the email, the site will reply with an email containing a sign up link. Upon clicking the sign up link, the user can then complete the sign up process.

On Doorkeeper, we use kara-mail to allow users to easily sign up to attend an event via their mobile.

Kara-mail Registration with Doorkeeper

Because mobile spam is particularly annoying, mobile carriers have a setting that will allow users to block all email that do not come from other mobile devices or a specifically whitelisted domain. To help users whitelist our domain, we link directly to the carrier settings page. Additionally, as most Japanese mobiles do not support copying of web page text, but do allow copying of form input text, we put our domain in a form input so a user can easily copy it.

Depending on the mobile carrier, we show an appropriate link to the settings. The links are

For more tips on designing for Japanese mobiles, see our Keitai Web Technology Guide.

For over a year, we have been helping with the organization of Mobile Monday Tokyo, a leading networking organization supporting the local mobile industry.  One challenge we faced with Mobile Monday Tokyo was at-the-door check-in, as finding a given participant required scanning through a list of over 200 registered participants.  To address this, we settled on distributing tickets with QR codes, which are ubiquitous in Japan.  As every standard Japanese mobile phone is equipped with a QR code scanner, this is a fast, easy to use, and cheap solution for handling at-the-door check-ins.

What began as a simple tool for checking-in attendees, evolved into a fully featured event management system.  Tailored to the needs of Mobile Monday Tokyo, we built a system that helps to

• register participants with minimal friction
• quickly check in attendees at the door
• engage the community of participants
• gather information about attendees
• sell tickets online

This event management system has helped to smoothly run many Mobile Monday events in Tokyo.

Enter Doorkeeper

The challenges faced by Mobile Monday Tokyo are similar to many other types of networking, industry and similar events.  So today we are opening this service to the public as Doorkeeper to allow everyone to take advantage of the easy ticketing and check-in it offers.

Doorkeeper delivers a compelling and cost-effective solution for many event organizers.  With Doorkeeper, we only take a small commission on tickets sold through our system.  No setup fees, no monthly fees, no other hidden fees.  You can use Doorkeeper to host your free events for free.

Why not try out Doorkeeper now?  Visit http://www.doorkeeper.jp/ for more information and to create your first event.

Also follow us on Twitter: doorkeeper_app