Attribution has long been a rung in the marketing ladder, being able to account for customers’ touchpoints as they progress through the sales funnel. But that slow-moving tide is turning into a tsunami.

Marketing attribution has stepped into the spotlight, and it is becoming a real priority across many top industries. In a survey conducted by the Interactive Advertising Bureau, digital marketers placed cross-channel measurement and attribution as the top focuses of their time for 2016.

For marketers in the subscription business, it’s vital to have a working knowledge of the main attribution models and why they’re used. At its core, attribution helps you get the biggest return on your marketing investment, deserving every scrap of attention you can spare.

From the First Step to the Last – And Everything in Between

Customer value can be broken down into just a few major models – Last Click, First Click, Linear, and Variable. Here’s a rundown of their pros and cons, as well as how they apply in the niche arena of subscription marketing.

1. Last Click: This is the bread and butter of attribution models. It’s the most commonly used and the easiest to track because 100 percent of the customer’s value is attributed to the very last click the customer makes with the marketing effort.

Imagine a journey in which a customer sees a display ad, then clicks on a page search, returns to the website through an astral search listing, and eventually decides to buy later on through an affiliate link. With the Last Click model, the affiliate would get 100 percent of the credit for converting that customer.

Last Click is useful because it illuminates exactly when the customer feels the impetus to buy. And because you don’t need any custom technology to delve backward into the customer’s journey, this metric is easy to find.

2. First Click: This model attributes 100 percent of the customer’s value to the very first point where the customer connects with the brand. In the aforementioned string of events, a First Click model would reward the display ad with all the credit because of the focus placed on the customer’s initial connection with the brand.

First Click is less widely used than the Last Click model, but it’s useful if you’re in the business of drumming up initial awareness and brand recognition.

3. Linear: In this model, equal credit is given to every single touchpoint in the customer’s journey, from the first viewing of an ad to the final purchase. It’s particularly useful if you need to establish a more complete picture of how your customers interact with you. But with that increased value comes a more complex method involving more custom technology.

4. Variable: It’s the most intricate, but also the most rewarding model. Unsurprisingly, it’s also the one recommended by Google attribution experts. As Google evangelist Avinash Kaushik once said, “Attribution is driven by experiments.” There is no one correct model; to succeed by looking at attribution, you have to play with variables until you get it right.

The Variable model varies the credit awarded to each channel based on a set of criteria determined on the client side, and it’s provided many companies with significant results. Hertz, for example, began employing a Variable attribution model, measuring every touchpoint of its ad campaigns. The company has experienced monumental improvement in its marketing efficacy.

Other attribution models are used, but much less frequently. For example, First Interaction would function similarly to First Click but could be triggered by an ad impression, even if a user does not click on the ad. Just make sure you utilize whichever model makes the most sense for your brand.

Attribution in a Subscription-Based World

Attribution in e-commerce is pretty simple to understand. Each transaction has a set value, so each customer’s effect can be succinctly measured and understood.

But subscription marketers face a slightly different challenge in how the value of transactions is calculated.

Because the initial transaction is only a fraction of a subscriber’s lifetime value, how does something like that get attributed? How much credit does each marketing channel get? Does the initial touchpoint become less and less relevant as each month passes?

Really, it’s best to meet somewhere in the middle. The first month is important for evaluating marketing efforts to make sure you’re investing in the right channel. Months three and four are also significant, but attribution will be less tied to that initial contact. It’s all about staying flexible. After all, no one model is right or wrong.

Ultimately, your ability to turn attribution into ROI will depend not on which model you choose, but how you utilize its insights. As Kaushnik rightly says, you must “take that rough output, make changes, observe the impact, identify insights, and be less wrong over time.”

So get that process started, and keep striving to be less wrong.