The Sales Funnel
Over the years the funnel has changed, I like to think of them as two types the traditional and the modern.In a nutshell, the sales funnel is called a funnel because you are taking a large audience and squeezing them to a sales page. This is the traditional "Funnel". Picture a funnel with a wide top where the audience enters and a narrow spout where the audience comes out.
The modern "Funnel" is more of a "Filter" than it is a funnel. Ultimately the result is the same, but it is slightly more focused and less obtrusive. The idea is to take a large audience and filter out the uninterested readers from the interested readers so that you can get better conversions. Having the audience pass through a series of filters and refining your filters as they pass so as to get better returns. This successive filtering is also known in the industry as "up-selling".
It is not uncommon to use both types of funnels, The traditional funnel is used to drive the traffic to the modern funnel.
The Hose
Think of a hose. A flexible tube used to convey fluids to desired destination. Hope you were not thinking of the other type of hose. "To cheat, or deceive". because that is not what affiliate marketing is about at all. The secret to a good hose is to master rhetoric. The hose is used to convince the reader into buying a product or to make a purchase with your affiliate. Again, and I stress this because it is extremely important; DO NOT try and deceive your audience. The hose is used to direct your audience to your affiliate's site. The site of the company that will make the final sale. I should point out, selling your own product is not affiliate marketing.
Okay, so how do you make a funnel and a hose?
The funnel is all about gaining traffic. You can have a narrow funnel and a wide funnel. A narrow funnel could be a simple blog about a specific topic. A wide funnel could be using social media sites to draw attention to a landing page or blog. Most social sites frown on using affiliate links directly on their site. Read the terms of your affiliate membership, often they forbid the use of posting direct links on social media as well. There are 1,000's of ways to make a funnel. The principle is always the same. Get an audience to view your affiliate ad.
In Summary
The width of the funnel is determined by the number of places viewers can see your funnel. The traffic is the number of people that fall through the spout. The spout can open up to a hose or to the affiliate site directly. Also, you can have a hose or many hoses lead to a funnel. Finally, if a person makes a purchase from your affiliate link, that is a conversion. Your goal is to have as many conversions as possible, because each conversion is money in your pocket.

