Affiliate Marketing
You're proud of your new company, Milly's Mac Maven. You specialize in all-things-Mac. To make money, you add affiliate marketing to the mix. You promote products you love and get a kickback for your efforts.
When the products you promote sell, you make a percentage. The key notion in affiliate marketing is that business interest in many venues...align. That is, someone selling dog food probably has a natural alignment with someone selling leashes and pet health insurance and flea spray (anti). So rather than a half dozen disparate efforts, why not align with one clearinghouse that is focused on reaching that demographic?
That's the foundation of affiliate marketing. And it exists today as one of the more liquid marketplaces on the web. That is, success and/or failure is known very quickly. Think: 72 hours after the beginning of a campaign. An affiliate network might include a load of, um, informational emails (ok, it's spam) and banner ads and fake news press releases like "This just in! Purina has new whale-flavored dog chow!"
Why does the immediacy matter? Because, across a full suite of affiliates, sellers get an immediately broad sample of a marketplace's feedback as to whether their creative work is good or not. And often, as a part of the service, the affiliate marketing manager (sometimes it's a whole company) will give specific feedback based on the data received. Like, "When we A/B rolled this campaign, we found that, when you gave a coupon for a dollar off the bag of Horse Hoof Chow, you got 18 times the click-through on the banner." So then the seller tweaks and tweaks and eventually optimizes their marketing spend.
With all of these dials to turn, obviously the back end or techy part of an affiliate network is...complex. Enormous sets of code need to manage data diagnostics, customer management, privacy, individual accounts, payments, conflict adjudication, and Russia. Yeah, Russia's always in there somewhere.