Is it possible to have “add to cart” links for more than one product on a page?
For example, on a page for a paperback book, I want to say that the subject matter is also available in an e-book, DVD, etc., and give the customer the opportunity to add it to the cart on the same page.
normally, for simple products, there is an add to cart button for each product listed on the page. Your theme may override this, but having the add to cart button on products in a summary page (with multiple products) is the default.
if you’re talking about having multiple add to cart buttons on the single product page (one per variation) that’s not currently possible, but it looks like it may be possible when they release 2.0, as they’re going to support add-to-cart url’s for variations (currently, adding a variation to the cart involves sending post data in addition to the usual query string)