Rationale - Why you should use RPX - Because normal users don't know what Open ID is
Enabling users to sign in to your site without having to remember a new password is clearly one of the best ways to increase participation and interaction in your site. I have seen quite a few more registrations on my sites since enabling Windows Live ID and Open ID, but I have had a lot more site registrations with Windows Live ID than with Open ID. The actual numbers are:
As of 2009-05-17
Open ID Registrations: 115
Windows Live Registrations: 1058
I think part of the reason is because there are a lot of Windows Live ID users, anyone with a hotmail or msn or live.com email address or anyone that previously had a Microsoft Passport account all have a Windows Live ID.
Over time, many account providers like Google, Yahoo, Facebook, and even Microsoft have embraced Open ID, so users who have these accounts have an Open ID account, but they don't know they have one, and if they see a standard Open ID sign in prompt like this:
they would not know what to enter there to sign in with their Google or Yahoo account. mojoPortal has built in support for direct Open ID sign in and registration using an input like the above. It authenticates directly with whatever provider is resolved by the Open ID url entered. But the point is, its not user friendly, only terchie people who know they have an Open ID account and how to login with it can use this. One early solution to improve this situation was the ID Selector widget from www.idselector.com
OpenID will work without a selector code, but adding the selector code enhances it with a nice selector for the various open id authentication services, so when the user clicks on the OpenID login text box they see this:
the idea of the widget is to make it easier to enter the correct url for your OpenID account, but still, the user would have to click in the sign in prompt to even see this and since they don't know what Open ID is they don't click it very much.
Enter The RPX Service
What is really needed is a more user friendly way to invite people to sign in or register with their existing accounts without having to know anything about Open ID or what it is. The RPX service from JanRain, provides this more user friendly sign in solution that is easy for users to understand and is much more likely to increase site registration than the standard Open ID sign in even if it is enhanced with the ID Selector widget. Below is what the user sees (and you can see it when you sign in or register on this site). You can configure which account providers are shown and in what order. If you enable more than 6, then the next ones are shown on a second page if the user clicks "More Providers".
This is much easier to understand, the user just clicks the account type they already have and are able to register or sign in without having to learn or remember a new password.
Setting Up The RPX Service in mojoPortal
Its very easy to get a free RPX account. Just sign in to your mojoPortal site as a user in the Administrator role and go to (Key icon) Administration Menu > Site Settings > Security > Open ID.
There you will see the inputs for entering your RPX API key and Application Name. If you already have an API key, you should paste it in and click he Setup RPX button. If you don't already have an RPX account, just leave it blank and click the Setup RPX button. You will be redirected to rpxnow.com where you can create an acount. After you create the account, rpxnow.com will automatically redirect you back to your site and your account settings will be configured automatically and your settings will be somethng similar to what you see below.
I expect to see a lot more site registrations using Open ID via the RPX service going forward. In the future I will update this document with actual results.