I would say that there are actually 3 components that you need as a minimum for your sales funnel, for sure 2 of them
This will be the squeeze page as first of its emails. Then to provide the freebie from your squeeze page you also need a download page. I would not send just a file per mail to the prospects. Having a download page has many advantagesclickfunnels pricing 2018.
When sending a mail with the link to your download page, your prospects learn click on your links
you can add additional products on this page (like affiliate links of related products)
You can also promote your blog, Facebook page and other social platforms
you can promote other products that you’ve created (cross promotion)
You can also promote high ticket offers there (like webinars)
So we have the 2 Must Have components of a sales fannel already, the squeeze page and the DL page. Now, the third component you need to make money with If you do not have an affiliate offer, It would not be your sales page in this case, but you have an option to earn commissions and make money.
Or you start your own product That means you will get your sales page after they sign up. If they buy you can also direct them to an upsell and so on, so it’s nice to keep them in your funnel But do not wait until you have your own product Go live with your squeeze page and download page and then work on your own product. As soon as you are ready with it, you use your own sales page after the opt-in and put your affiliate product that you have already used to download page (so you can get commission). Keep in mind that you also need a download page.
So from the download page we have a link going to the affiliate offer. As long as you keep creating new products (for upsells and downsells) you keep your funnel and can always add new products … as soon as you direct them to a affiliate offer (not on your download page but after they buy one of your products) will you “lose” them in your funnel (of course you still have their email list)