While it is always fun to dissect and extrapolate on imaginary numbers , the only fact that I am certain about when it comes to TF is that they are a privately held company and do not publish their financials. So to start doing the math based on what the TF salesman throws out in a conversation is next to useless. Lets face it, the local TF rep has no more inside knowledge of the big financial picture at TF other than what he is allowed to know and fed on an ongoing basis.
With one of the other guys in the WS business at least you have a fighting chance if you want to pour over quarterly numbers and year ends.
As well assuming any "average" for what a website produces for the "average florist" is next to useless as I see no reason why the old 20/80 rules (or a slight variance of it) would not apply here. The volume a website does is so dependent on so many factors, size of town, optimization, ad words, selection of product, effort invested, etc. Most florists do little if anything to improve or promote their websites, they uses the "field of dreams" system (you know..."build it and they will come") that is why cookie cutter sites are used by so many. Pay your $99.00 per month and sit back waiting for the orders.
It is also why such a large concentration of orders are in so few hands, the companies generating the bulk of the business on line treat e-commerce as just that a "business" onto itself. This is a mind set that the typical 'mom and pop" florist just do tend to embrace, after all they B&M business to operate daily.
As far as how many orders TF sites actually generate, who cares? The only web site volume any of us should be focused on is our own. Knowing that TF sites generate 2.4 million per annum, or 2.4 gizillion per annum doesn't mean getting one will change any shops business for the better.
Lets face it, most of the "florist" canned websites are not much different in nature, what separates the men from the boys is what an individual shop does with their site.