The impact of advertising on sales and demand

Welcome to the World of Advertising Economics!

Ever wondered why companies spend millions on a 30-second Super Bowl ad? Or why some brands can charge double the price of their competitors for almost the same product? In this chapter, we dive into the microeconomics of advertising. We’ll explore how firms use advertising to change our minds, shift demand curves, and build "moats" around their businesses. Don't worry if you find economic graphs a bit dry—we're going to break this down using real-world examples that make sense.

1. Why Do Firms Advertise?

In a perfectly competitive market (which you might remember from earlier chapters), products are identical, and firms are "price takers." In that world, advertising is a waste of money! However, in the real world of Monopolistic Competition and Oligopoly, firms use advertising to stand out.

There are two primary ways advertising works:

Informative Advertising

This is all about providing data. It tells the consumer about the product's existence, its price, its features, and where to buy it. This is very common for new products or technical goods like computers or insurance policies.
Example: A local grocery store flyer showing that milk is on sale this week.

Persuasive Advertising

This is designed to create a "brand image" and convince consumers that a product is better than its rivals, even if the physical differences are tiny. It aims to create Product Differentiation.
Example: A perfume ad that shows a glamorous lifestyle but tells you absolutely nothing about how the perfume actually smells!

Key Takeaway

Informative advertising helps markets work more efficiently by giving consumers facts, while persuasive advertising aims to change consumer tastes and build brand loyalty.

2. The Impact on the Demand Curve

This is a core part of the CB2 syllabus. Advertising is designed to influence the demand curve in two specific ways. If you can visualize these two movements, you’ve mastered half the chapter!

A. Shifting the Demand Curve Outwards

Successful advertising increases the total number of people who want the product at every price level. This shifts the demand curve to the right (from \(D_1\) to \(D_2\)). This allows the firm to sell a higher quantity at the same price, or even a higher price.

B. Making Demand More Inelastic (Changing the Slope)

This is the "magic" of branding. By creating brand loyalty, firms make consumers less sensitive to price changes. If you are a die-hard fan of a specific smartphone brand, you might keep buying it even if the price goes up by $100.
\nIn economic terms, the demand curve becomes steeper (more inelastic). This gives the firm more Market Power to raise prices without losing too many customers.

Quick Review:
\n- Shift Right: More people want it.
\n- Steeper Slope: People are willing to pay more because they are "hooked" on the brand.

3. Advertising and Price Elasticity of Demand (PED)

There is a fascinating tug-of-war here.
\nInformative advertising can actually make demand more elastic (flatter) because it informs consumers about cheaper alternatives, increasing competition.
\nPersuasive advertising makes demand more inelastic (steeper) because it convinces consumers that there are no close substitutes for their favorite brand.

Memory Aid: The "Rubber Band" Trick
\nThink of Elasticity like a rubber band. If demand is Elastic, consumers "stretch" away to other brands the moment you raise prices. If advertising is successful, it "snaps" that rubber band, making demand Inelastic—consumers are stuck to you like glue!

4. Finding the "Optimal" Amount of Advertising

How much should a firm spend? A firm shouldn't just spend money blindly. They follow the Marginal Rule.

A firm should increase advertising up to the point where the Marginal Cost of Advertising (\(MC_{adv}\)) is equal to the Marginal Revenue/Profit (\(MR_{adv}\)) generated by that advertising.

If spending an extra $1,000 on ads brings in $1,001 in extra profit, do it! If it only brings in $999, you've spent too much.

Did you know?

In industries like pharmaceuticals or perfumes, advertising costs can sometimes make up over 20-30% of the total revenue! This is because the physical cost of making the liquid in a perfume bottle is very low, but the cost of "selling the dream" is very high.

5. Advertising as a Barrier to Entry

In the "Microeconomics of Firms" section, we look at how big companies stay on top. Massive advertising budgets can act as a Barrier to Entry.

1. Sunk Costs: Advertising is a "sunk cost." If a new firm tries to enter the market and fails, they can't sell their "used ads" to get their money back. This makes entering the market very risky.
2. Brand Proliferation: Large firms might launch 20 different brands of cereal to take up all the "mental space" (and shelf space), making it impossible for a small newcomer to be noticed.

6. Common Mistakes to Avoid

Mistake 1: Thinking advertising always increases profits.
Don't forget that advertising is a cost! If the cost of the ad campaign is higher than the extra revenue it brings in, profits will actually fall.

Mistake 2: Confusing a "movement along" the demand curve with a "shift."
Advertising shifts the curve. A change in the price of the product itself causes a movement along the curve. Make sure you use the right terminology in your exam answers!

Summary: The "Big Picture"

Informative vs. Persuasive: One gives facts, the other builds "vibes" and loyalty.
Demand Impact: Successful ads shift demand right and make it more inelastic (steeper).
Elasticity: Branding reduces the number of perceived substitutes, giving the firm more power to set prices.
The Limit: Stop advertising when the cost of the next ad equals the profit it brings in (\(MC = MR\)).
Barriers: Huge ad budgets make it scary and expensive for new competitors to join the party.

Keep going! You're doing great. Understanding how firms manipulate demand through advertising is a key step in mastering the behavior of firms in CB2.