How to find companions and form a group for a bicycle tour

preface
I found it easiest to not have a group size in my head. One of the participants actually had her partner drop out just before the start and thus did not think again of a coast to coast for almost 20 years (time constraints took over). Out of 25 serious responses, I had a committed list of 10, of which I hope 6 will start.

timeline
9 months before: post an open (not expiring until a month before your tour) ad in either Adventure Cycling or CrazyGuyOnABike. Some of the the AC ads are printed right in the hard copy of the magazine and the rest are an addendum on their website. At least two of the people who responded right away are still committed. From this ad about 50 responses were generated. About 50% of those were just commenting or had general questions about long distance touring.
Here is a copy of my ad, which answered most people's questions before they emailed me:
Cross Country 2010 created: 07/24/2009
45-year-old married female looking for touring partners interested in a late-May or early-June crossing of the U.S. via the TransAm or Northern Tier - both are acceptable. I travel self-contained, camping mostly, averaging 50 miles per day at about 11 to 13 m.p.h. Will stay at hotels when needed for shelter or a shower. I generally eat a hot breakfast at a restaurant. I'll travel east to west (no morning sun in the eyes, avoid cold in the western mountains). If interested, email.

logistics of forming the group
One of the most difficult tasks has been the emails and keeping track of who is doing what. You would think that would be easy for me (being geeky), but it entails organizational skills. As people responded to my junk account (don't put your good email address in the ad), I attempted to assess whether they were really interested, then started sending those people emails from my good account and told them to take note of the different address. Next, I created an email group in this account specific to this tour, then created a word processing document using the styles feature, so I could identify each person's name as a heading (this allows me to have a little sidebar which shows only headings and jump to anyone's name). Lastly, I put a note next to their name indicating their commitment and color coded the names with green (may come) or red (not coming). The note shows in the sidebar, but the color does not.

diplomacy
I did not want to be a tour leader. We have had some democratic discussion about: route, style of travel and where to stay the night before the start. The benefits of a larger group of people about whom you know little to nothing is that sub-groups can form and you can meet up at the end of the day for the camaraderie.

things I would do differently (as of pre-tour experiences)

• Weekly, I would start a new subject (conversation thread) and address it directly from my dedicated email group and not rely on "reply to all with history".
• I would find a way to keep track of the last time each person responded to check that they are not lost in cyberspace.