The goal of a landing page is to assist users to find the right item to purchase. They don't know exactly what they want yet. People who know what they want will search for it. Most successful landing pages are designed with exposing categories to people, grouping products together in logical groups that consumers can easily digest.
Here you can see Apple, instead of trying expose all of their products, are focusing the Store landing page on similar products that are being pushed in current marketing campaigns. If you browse farther down the page (not in the screenshot), you get a carousel and grid layout of items relating to the category of iPhone and iPad devices. There's nothing here about the MacBook or Mac Pro or Thunderbolt displays. It's focused on what most people are buying.
Again, you see here that the focus isn't on quantity of product but relative quality to the user. Here Amazon has a few promotions that they think I may respond to. After that, the rest of the page are product carousels based on items I've looked recently, saved in my cart, or added to a wish list. Amazon is trying to say, 'Hey remember this one thing you looked at but didn't buy? Well here's a bunch of similar items that are kind of like it, but you might like more."
Zappos takes a slightly different approach: main advert, category links and then starting to bubble up shoe recommendations.
Netflix is "selling" movies. They want you to watch stuff. So to help with the perennial problem of "what should I watch now?" Netflix inserts category carousels with movies similar to movies you've watched previously.
The important takeaway from all of these examples is that while the number of products shown varied, they all focused on how they could focus the user's choice parameters by providing similarly grouped items together. People weren't shopping with computers and phones next to each other, or kids and action movies. They're focusing on how their pages can be more browsable (and therefore more consumable) to users.