MGT 100 Week 8
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Importance of Customer Acquisition
Market size: How many customers experience the core need?
Diffusion: How does the served market change over time?
CLV: How profitable are customer relationships?
\(\text{BrandRev.} = \sum spend \equiv \sum \frac{stores}{1} \frac{cards}{stores} \frac{transactions}{cards} \frac{spend}{transactions}\)
Which of the four factors do you expect to explain most of the variation in revenue? Why?

The correlation holds remarkably well across different levels within the data. Which factor best predicts revenue? Was it what you expected?

The correlation holds remarkably well across industries, illustrating its generality. What does this imply for prioritization among these four variables?
Data always describes the past, but decisions affect the future. Predictive analytics help to convert past data \(X\) into decisions \(A\) to maximize expected utility of outcomes: \[\arg\max E[U(A,Y) | X]\] Examples include election forecasts, product recommendations, and fraud prevention

Predictive analytics is seductive, as astrology or “picks of the week” suggest. Where have you seen people misunderstand or overinterpret a prediction?

Dray has a powerful predictive analytics engine between his ears. He knows what will happen next after someone puts on their shoes and picks up the leash. But he doesn’t always know why–he is less good at diagnostic analytics
Market size counts both purchasers and non-purchasers who share the core need. Past purchasers can often be counted, but non-purchasers usually can’t
Each method has different blind spots — top-down requires estimating Unserved, bottom-up ignores Unserved, analysts have incentives.
Market size predictions usually require assumptions. “Sensitivity analysis” shows how much results differ when you vary the assumptions. What changes if mattresses last 5 years instead of 7? How much do those analyst estimates cost?

Diffusion curves show how SAM changes over time. Adoption is often an S-curve: slow start, accelerating takeoff, saturation, eventual decline. Blue is the density, Yellow is the CDF. Sometimes a “Dip” phase appears between early adopters and early majority; sometimes a “Decline” phase follows maturity. Also appears in epidemiology, with adoption recast as infection and influence recast as contagion

There are claims that diffusion is speeding up

Digitization and social media are plausible mechanisms for accelerating diffusion curves, but these products are not randomly selected. Large majorities of products get lost in the multitude

In food and drug channels, 35-40k new SKUs launch each year; 90-95% fail completely within six months (Wilbur & Farris 2014). Why is product failure so common, and why do firms keep launching anyway?

New products launch frequently, but most fail, and success is notoriously unpredictable. Addressing a real core need is necessary but far from sufficient. Which of these would you bet on?
A “differential equation” model relates the level of a variable to its derivative. Fits sigmoid curves well
\[\frac{dA(t)}{dt}=pR(t)+q\frac{A(t)}{M}R(t)\]
LHS is growth per unit of time. 1st term on RHS indicates those who would buy regardless of others’ choices (“innovators”), which is assumed to be a constant proportion of the unserved market. 2nd term is those whose purchases are influenced by others (“imitators”), increasing in proportion of market that is served
\[\frac{dA(t)}{dt}=pR(t)+q\frac{A(t)}{M}R(t)\]
\[A(t)=M\frac{1-e^{-(p+q)t}}{1+\frac{q}{p}e^{-(p+q)t}}\]
You don’t have to know how to solve differential equations for this class. Just take my word that the 2nd equation is the solution to the 1st equation.
NLLS is a straightforward generalization of OLS in which the errors can be nonlinear in the parameters. Parameter estimates are still chosen to minimize the sum of square errors, but they don’t have closed-form solutions
If we want, we can solve the system of 3 equations in 3 unknowns to recover \(\hat{p}\), \(\hat{q}\) & \(\hat{M}\) from \(\hat{\beta}_0\), \(\hat{\beta}_1\), & \(\hat{\beta}_2\)
\[\hat{\beta}=(X'X)^{-1}X'Y\]
\[min_\beta (Y-X\beta)'(Y-X\beta)\]
\[min_\beta [X'(Y-X\beta)]^2\]
“In theory, there’s no difference between theory & practice. In practice, there is.”
Some theoretical models offer multiple estimators. Some have no estimators
Estimators may yield different estimates due to assumptions, numerical properties
Subfields that invent estimators and study their properties: “econometrics,” “data science,” “machine learning,” “statistics”

These figures are from Bass’s original 1969 paper. Compared to having no predictive framework, these were like magic to investors and managers. But look closely– although retrodictions are often near-right on average, every individual retrodiction is wrong
Everett Rogers was a professor at UNM who spent 50 years studying the “diffusion of innovations,” which now includes over 5k published studies. Rogers’ framework is the most widely used to explain and predict new product success/failure. Pick a product and score it on each dimension
Bass + Rogers offer the most widely used framework, but neglect important alternate explanations
Classic conundrums in viral marketing: Should you seed the experts, the taste makers, the network-central hubs, or those with track records of relevant influence? When and whom should you gift vs. pay to promote?

I love Citron’s flat priors and bias for testing. It fascinates me that half the team thought the idea was bad, but they proceeded anyway. I wonder which half he was in?
I missed a lucrative boat before I found my calling. Should I tell you the story?
Google started Trends back in the 00s because it worried about SEC regulation, given that its search data could predict stock price movements. Seems quaint
CLV can account for customer heterogeneity using same approaches we talked about in week 5
Republican Utah might not be your first guess as to whom invented Housing First, but it CLV analysis made this dramatic policy shift look like a no-brainer
Basing policy choices on CLV requires us to quantify and clarify our assumptions, and shows how we expect policies to impact customers. Quantifying disagreements facilitates next steps toward resolutions. What are possible next steps toward evaluating how Housing First policy attributes affect homelessness?
\(T\) is often set at 3 years, but Bezos says Amazon’s 7-year horizon lets them justify investments competitors can’t match. The horizon, retention, and discount rate are all judgment calls. Prediction uncertainty increases with \(T\)
Most common “fudge factor” values: 3 or 7. Why?
Firing customers can be direct/confrontational or indirect/quiet. Better yet, redesign product menus and reprice so that unprofitable customers either become profitable or self-select out

This graphic shows total gambling industry net revenue as a function of gambler net spending percentiles. 5% of gamblers cost online gambling operators 20% of their revenue, whereas the most profitable 3% of customers generate half of net revenue. Operators block and limit frequent winners, so pros use “beards”
Assume price is $100, margin $50, retention 50%, discount rate 10%, horizon T=1: CLV = 50 + .5 * 50 / 1.1 = $72.72
Suppose you consider increasing price to $120, holding all else constant: Then, CLV = 70 + .5 * 70 / 1.1 = $101.82
Should you raise the price?
When can CLV analysis optimize price?

Suppose you consider a 28-period time horizon, with true \(p=.03\), true \(q=.1\), and \(M=435\). Simulate data from these parameters. Now suppose you only had data for periods 4-12, supposing that measurements for periods 1-3 are unavailable. Use OLS and NLLS to estimate the Bass model based only on data from periods 4-12. Then use both estimated models to make out-of-sample predictions for periods 13-28. Calculate mean square prediction errors in periods 13-28 for both models. Visualize the two MSPEs to illustrate which estimator generalized to the non-training data better.


