Amazon.com has a major presence at the Internet Merchants Association (IMA) conference taking place in Las Vegas this week. Online merchants, many of them high-volume sellers with a presence on eBay and Amazon.com, attended a session titled Amazon Best Practices for Selling Online, and Amazon's roundtable sessions on Tuesday afternoon were packed with sellers eager to get answers to specific questions.

Amazon.com executive Matt Williams presented the session on Best Practices. He told attendees that 26% of total units sold on Amazon are from 3rd Party Sellers and there are 1.3 million worldwide active seller accounts.

Williams said Amazon innovations include being the first and only major retailer to open product detail pages to 3rd party sellers and is extending its open approach to include fulfillment and to open back-end and commerce capabilities to sellers.

There are three major areas around Best Practices: Create quality listings to capture buyer interest; Amazon is different than on other ecommerce channels; Deliver world-class customer service.

Specific advice included: Use quality product images and detailed product information, and list everything you carry. Williams said offering 100 percent of your inventory items on Amazon.com makes a big difference to sales you can generate.

Amazon used the opportunity to outline the Fulfillment By Amazon (FBA) program and WebStore By Amazon ecommerce offering and pitched merchants on why they should consider using those programs.

Williams said it's free to get started with FBA (storage fees start when product arrives at the Amazon warehouse), and they've seen a significant increase in a number of merchants whose sales increased due to Amazon's Super Seller Shipping & Prime shipping programs. (When asked earlier in the day whether merchants carried the shipping cost for those orders, an Amazon.com spokesperson said it wasn't a yes or no answer, and details were available on the Amazon website.)

One seller said FBA has greatly improved since the fall. She asked whether Amazon was including ad inserts in Private label boxes in the FBA program. Williams said yes, but they are looking into this. "Ideally we'd like sellers to be able to specify the inserts they'd like to include," he said.

Williams said it makes a big difference to buyers that they can use their Amazon credentials on a seller's WebStore By Amazon. He compared the Amazon payments availability on WebStore to logos merchants use on their own websites to help buyers have trust in the merchant.

Amazon uses its historical experience to upsell and cross-sell on a merchant's Webstore if they plug into the Amazon catalog, such as Amazon Recommendations. There is a zero inventory risk to determine what you should sell on your website by selling Amazon products on your website - and earn affiliate commissions - according to Williams.

Amazon includes a link to a merchant's Webstore from the seller's merchant information page on Amazon, which drives some traffic and also adds a boost to the merchant through the link. In addition, WebStore sends feeds to Google Base and Froogle.

Williams said WebStore advantages also include professional design; Search Engine Optimization; Selection and price; and Microsites where sellers can create complementary sites or niche sites.

There was little time for questions from the audience, but Amazon.com was hosting roundtables throughout the conference where it took questions from attendees, and its table was consistently filled with sellers.