Following is the email I sent (sans the names and companies, plus some spelling fixes).

Wanted to give you a brief recap of what we have seen to be successful with running events online.

1. Find Your Audience Online
This is basic and practical I know, but many companies don't really get a good lay of the land far enough in front of the event to be successful. The idea is NOT to be a total new comer to the conversation and expect people to ride in and support the effort.

Part of this effort should be around ad support and potential sponsorships in those key communities months before the event.

As part of monitoring the online audience, look for themes that arise as part of the conversation. This gives you content fodder for mini-events (#3 below).

So getting some brand visibility is key. The visibility needs to be focused on the influencers.

2. Set Up Your Online Presence
Social media is fueled by reciprocation, be it tagging, friending, commenting or viral applications. But, there's got to be some place for people to see who you are what you're doing. Options (among others) could be a blog or microsite, Facebook group or page. Somewhere that gives you the ability to post content, notices and updates about upcoming events.

3. Create Mini-Events
Trying to get large audiences online is dependent on either: (a) celebrity draw, or (b) unique, interesting and relevant content. In front of the event itself create mini-events such as online chats using UStream or Kyte player. So you can take some people involved with the main show and start creating content and events that would be of interest to your crowd. During these mini-events your always throwing messaging forward to the main event.

4. Cause Marketing
This one has potential to work extremely well. Through cause marketing you can tie the event to a charitable cause. You can leverage the non-profit network to promote the event, and you can do something around say attendance numbers. So for each online viewer we will donate $1 up to 100,000 dollars. Obviously this costs money, and we only recommend this strategy if the organization itself is building a sustainable online community. With cause marketing you're driving lots of visibility and traffic and if the idea is to sustain a community beyond the event then it's an effective and comparatively inexpesnive way of doing it.

5. Main Event
In the online world, we have found promoting an event by communications outreach too far in advance is a waste of time. For exposure use brand advertising or site sponsorships as mentioned in point #1 above. For the event itself use the mini-events as a way to keep people interested then do your outreach online max four days in advance. Have something interesting and exciting to talk about for the outreach (see point #6 below) is critical.

6. Post Main Event
Another great tactic we have used is a post-event community program. That is a live call or online chat after the event where people who just watched the telecast can then get on and talk about it. This gives great reason to do outreach: "Don't forget to tune into the Telecast at 9 p.m., and then join in the Live Chat/Audioconference/Blog Radio Show with XXX immediately after."

7. Create Calendar Items that Can Go Viral
Calendaring for events is one of the main reasons we like Facebook. Events are one of the most viral applications in Facebook. So if I'm interested in the event, I'll click on attending the event, and all of my contacts will see: "James is attending the XXX event at 9 p.m. on Thursday". So if my circle of friends on Facebook are also passionate about the topic, they now see it.

Now, one point not raised is e-mail. This discussion was based on the assumption the client didn't have an active email list.

BTW, most people stumble and fail miserably at Step 1, never giving the following six steps a chance.