One thing you can do is if you plan to buy on amazon, you can input the order and then before you pay, send a copy of the order to the actual company and ask if they can give a discount if you place the order directly through the company. Most will do the deal outside of amazon because they save money on the amazon fees.
Interesting how this demonstrates that showrooming can affect online retailers too. Popular retail websites that introduce consumers to products can lose out on the sale if a discount is available by buying directly from a merchant, just as physical stores can be bypassed if a discount is available from an online seller.
Most people probably won't take the initiative to make an enquiry with the merchant for an Amazon marketplace order, and it'd be too inconvenient to do this consistently for small purchases, but maybe part of the motivation for promoting merchants tied exclusively to Amazon is an awareness of the threat that online showrooming might pose to some of their business in the future.
