If you search around you'll find a number of case studies on this topic as it's a very common question (hint: try looking at Adobe's Scene7, it's an image serving solution and likely a good place for data).
The basic answer is that, especially when dealing with personal and household goods (things people wear / show and thus need to be sure look good) photos are beyond important. This isn't just a question of numbers and angles; having quality shots both to layout the product (flat background) and ideally in context (on a person/ wrist / etc) will raise conversions sharply.
The web is impersonal. Getting past that as much as you can is nothing but upside.