There are a lot of good choices when it comes to web conferencing software, and Adobe Connect is definitely one of the best, but each platform has its strengths and weaknesses. The most important thing is to decide on the list of features you need--and what sort of experience you hope to offer attendees--and work from there.

Some platforms are specifically designed for training. As far as I know, the only ones with built-in ecommerce capabilities are WebEx Training Center and InstantPresenter, both of which tie into your company PayPal account.

We're currently using WebEx Event Center because we need a 1,000-person room and want a group chat room where all the attendees can interact during our events. Very few platforms are stable with groups of 1,000, so that's one of our most important criteria, which perhaps wouldn't matter at all to you.

Here's a long shopping list of questions that you could start with before you begin comparing various platforms-

• What size meetings do you plan to host? Pricing is usually based on meeting room size.
  
• In addition to loading and sharing slides and other docs, desktop sharing, and whiteboard (the basic package), what else do you need?
  
• Streaming video of presenters? (becoming more common)
  
• Video of other participants? (less common but available in smaller platforms)
  
• The ability to hand off control to participants? (most will support this)
  
• Do you want to assign homework and have attendees turn it in via this platform? (only in specific training packages--Elluminate, WebEx Training Center)
  
• Do you need break out sessions where small groups can discuss/brainstorm? (again, training/education-focused platforms)
  
• Do you want to be able to quiz attendees?
  
• Do you want a group chat room for participants? (very important to us, but not everyone wants this)
  
• Do you want everyone to see the Q&A or only the moderators? (You'll see the hidden Q&A used in a lot of product demonstrations)
  
• Do you need to hand out documents in the meeting--pass them to attendees? This useful feature often doesn't come with larger "room" sizes because of bandwidth issues.
  
• How much do you want to spend?
  
• What kind of reporting do you need?

I could go on forever, but you get the point: decide what you need, then shop the platforms. The leading ones are Adobe Connect, WebEx, GoToWebinar (or the smaller GoToMeeting), and Microsoft Office Live Meeting. Others worth looking at are Elluminate, DimDim, omNovia, and InstantPresenter. There are a lot of promising newcomers, too, that I'm keeping an eye on but wouldn't consider stable enough to run our events on at this point.