It happened again. The client asked me if we could use Flash for "fluid movements" when we redesigned their e-retailing site. They wanted more animated graphics. In a perfect world, business owners would stop asking to make the web site user experience more complex by introducing movement. Meanwhile, see what usability guru Jacob Nielsen says about moving site elements here.
In my opinion, unless you have a significant budget, such as iHotelier, I would always recommend HTML over Flash for e-retailing web sites. It's very hard and quite time consuming to do Flash sites right. If you have a big budget, see how iHotelier did it. Source: User Interface Engineering