Directories fuel affiliate marketing. While some companies choose to keep their affiliate network separate from other products, the directories that connect affiliates with merchants are driving the world of affiliate marketing.

Part of this is due to the simple fact that directories make the process much easier for the affiliate. The marketplace in each affiliate directory categorizes affiliate products according to niche or product type, putting many possibilities at the fingertips of each affiliate. Because a merchant desires to have the greatest possible number of affiliates, the only logical decision is to list a product in a directory, as that is where the most affiliates are.

In order to stand out in an affiliate directory, merchants must be willing to provide the highest commission and have the best converting product. This competition ultimately results in better circumstances for the affiliates. Because commissions and conversions increase as the result of competition, more affiliates are drawn into the directories, prompting more merchants to list their products there.

The largest affiliate network, Clickbank, consists of only digital products. Because there is no overhead to producing digital products, and because they cost very little to duplicate, merchants are able to offer very high commissions to their affiliates. Instant scalability, the phenomenon that digital products cost almost nothing to reproduce, allows merchants to pay high commissions while still turning a profit, and it is a main reason why Clickbank has become the standard in affiliate marketing.

Clickbank organizes the products in its marketplace according to gravity. Although a combination of unknown elements determines gravity, it is the most attractive stat to affiliates, because the products with the highest gravity are often the best converting.

However, there are indeed plenty of affiliate directories for affiliates of physical products as well. Commission Junction and LinkShare are among the most popular hub for affiliates for household corporations. Although commissions are often lower for these types of transactions, there is often less of a need to sell a product. This is due to the fact that name brand products usually have a rapport with the potential buyers, while consumers of digital products need to be sold before purchasing.

Affiliate directories have many categories, which tend to satisfy every affiliate marketer. A search in any directory will bring many results, allowing a marketer to target any niche with one or several products. This not only gives marketers the ability to market multiple products, but it allows one to instantly compare the products available according to the percentage of the payout, the dollar amount paid on a sale, and even the conversion rates of a given product.

Affiliate directories are partly responsible for the boom of affiliate marketing in the last several years. By giving affiliates the opportunity to market many high paying programs, directories continue to be at the center of affiliate marketing.