We must be using different Internet or maybe the website I browse aren't flash heavy. I cannot recall a single instance where I thought... "Damn! If only I had flash on my iPad/ iPhone."
Try browsing for a new car or clothes. For whatever reason both of those verticals are highly dependent on Flash and as such unusable on the iPad. I would have thought luxury brands would have figured out by now that iOS demographics trend affluent and should be valued. Update: Case in point... http://hugoboss.com - usable mobile site, but you can't see or buy any of the clothes! http://bananarepublic.gap.com/ - "Fla…
Due to broken bones which forces me to stay at home, I've bought clothes online and it has resulted in a significant number of unpleasant surprises which are trivial to avoid in a physical shop. My (Danish) experience is that the shops that provide the most useful information are the shops that avoid Flash and uses plain html pages (e.g. Amazon, smartguy.dk).
Flash-based sites almost always makes it impossible to add "I probably want to buy this" bookmarks in the browser, so a lot of items don't get bought by me. So even when the browser supports Flash, the site starts out with a significant handicap (looking at you, H&M) ... and I don't have the patience for the transition animations that most Flash developers think is a must-have.