How do e-commerce websites work on the iPad?

Should etailers think about designing apps or special versions of their websites for the iPad, or will the existing websites do the job? 

Whether these sites need to adapt for the iPad or produce apps is debatable at the moment, since the number of users of the device is still small, but it may be something they will have to think about in future.

I've been trying out a few e-commerce sites on the iPad, and I've listed some of the usability issues that iPad users may face.

Small font sizes

Though great for browsing the web, iPad screens are still smaller than those of most laptops and PCs, so some text can be hard to read on them. 

This means that text-heavy pages, such as Amazon's product pages, can be hard to read without zooming. 

Drop-downs are redundant

Since you can't hover over links with a mouse when using an iPad, some aspects of websites don't work at all, or else very poorly. On the e-commerce sites I tried, drop-down menus on the homepage were a pain on the iPad. They only flash up for a fraction of a second, meaning that you cannot use them to find a quicker route to sub-categories. 

When using both M&S and ASOS, the drop-downs didn't stay there long enough to be of any use, and instead take the iPad user straight to the category. In the case of M&S, this isn't too bad, since I can then navigate within that category using the left-hand navigation options. 

On ASOS, however, there is no alternative to browsing via the drop-down menu, so visitors using the iPad are at a dead end. In fact, the only way I could find to view any products on the site was via site search. 

On John Lewis, the drop-downs remain visible after one click, which means they can be used as intended: 

The next problem though, is that the links on the drop-down are so small that clicking the one you want can be tricky. 

Links too close together

A mouse is a precise tool for clicking on links, but on touchscreen devices, clicking on links accurately can be a problem. 

One common problem is links that are placed too close together, making it virtually impossible to select the right option, as is the case with the navigation options on the left hand side of Amazon UK:

Flash elements not working

Given Apple's aversion to Flash, sites that rely on Flash too much are not going to work well on the iPad. The most extreme example is River Island, which doesn't work at all on iPad: 

Also, if you view Ikea on the iPad, there are huge blank spaces: 

Product photos and videos

Flash is often used for product display, whether through videos or pictures, and these elements don't work on iPad. I'm not suggesting that etailers should avoid Flash for this purpose, but it's worth seeing how these elements looks on an iPad. 

For example, on ASOS, the zoom tool doesn't work at all, since it relies on users moving the cursor to view, while on Schuh, the excellent 360 views of products just produce a blank box: 

However, while John Lewis and other sites don't have any alternatives, you can still see some excellent product photos from a range of angles:

Cluttered / busy websites don't work well

The more elements and text you place on a page, the harder it becomes to read and navigate on an iPad. For example, this product page from Tesco doesn't come across well: