1) I spend time working on my IM business during my crappy day job so I have no soundcard. Otherwise I work on it when my wife is watching tv or when I'm in bed. I don't want to have to wear headphones just to get the info I want.
2) I much prefer to read at my own pace and know where to skip to from a introductory menu. Find a specific piece of information is a real pain in a 30 minute video.
3) Sometimes the person doing the webinar comes across badly (they may seem boring, over animated or just the type of person I wouldn't warm to) - even if the info is good this can ruin the product because you are forced to look at them to get the info.
4) And most importantly. I spend a great deal of time reading up and researching on my mobile device because it's just so handy and accessible and I travel around a lot. Pdf's are no problem, I can read them direct from my dropbox but webinars are a no go.
Am I the only one who thinks this way? Do they really convert more than regular text based sales?