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Explore the multi-billion-dollar online advertising industry, its growth, key drivers, and the emerging discipline of Computational Advertising. Dive into revenue models, auction mechanisms, and user interaction with ads. Understand the diverse statistical challenges and opportunities in the realm of online advertising.
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Statistical Challenges in Online AdvertisingDeepak AgarwalDeepayan Chakrabarti(Yahoo! Research)
Online Advertising • Multi-billion dollar industry, high growth • $9.7B in 2006 (17% increase), total $150B • Why this will continue? • Broadband cheap, ubiquitous • “Getting things done” easier on the internet • Advertisers shifting dollars • Why does it work? • Massive scale, automated, low marginal cost • Key: Monetize more and better, “learn from data” • New discipline “Computational Advertising”
What is “Computational Advertising”? New scientific sub-discipline, at the intersection of • Large scale search and text analysis • Information retrieval • Statistical modeling • Machine learning • Optimization • Microeconomics
Online advertising: 6000 ft Overview Pick ads Ads Advertisers Ad Network Content User Examples:Yahoo, Google, MSN, RightMedia, … Content Provider
Outline • Background on online advertising • Sponsored Search, Content Match, Display, Unified marketplace • The Fundamental Problem • Statistical sub-problems: • Description • Existing methods • Challenges
Different flavors Online Advertising Revenue Models Misc. Ad exchanges Advertising Setting CPM CPC CPA Sponsored Search Display Content Match
Revenue Models CPM CPC CPA Cost Per iMpression Ad Network Pick ads Ads Advertisers Content $$ User $ Content Provider
Revenue Models CPM CPC CPA Cost Per Click Ad Network click Pick ads Ads Advertisers Content $$ User $ Content Provider
Revenue Models Advertiser landing page Cost Per Action CPM CPC CPA Ad Network click Pick ads Ads Advertisers Content $$ User $ Content Provider
Revenue Models • Example: Suppose we show an ad N times on the same spot • Under CPM: Revenue = N * CPM • Under CPC: Revenue = N * CTR * CPC CPM CPC CPA Depends on auction mechanism Click-through Rate(probability of a click given an impression)
Auction Mechanism • Revenue depends on type of auction • Generalized First-price: • CPC = bid on clicked ad • Generalized Second-price: • CPC = bid of ad below clicked ad (or the reserve price) • CPC could be modified by additional factors • [Optimal Auction Design in a Multi-Unit Environment: The Case of Sponsored Search Auctions] by Edelman+/2006 • [Internet Advertising and the Generalized Second Price Auction…] by Edelman+/2006
Revenue Models • Example: Suppose we show an ad N times on the same spot • Under CPM: Revenue = N * CPM • Under CPC: Revenue = N * CTR * CPC • Under CPA: Revenue = N * CTR * Conv. Rate * CPA CPM CPC CPA Conversion Rate(probability of a user conversion on the advertiser’s landing page given a click)
Revenue Models CPM website traffic CPC website traffic +ad relevance CPA website traffic +ad relevance +landing page quality Revenue dependence Relevance to advertisers Prices and Bids Ease of picking ads
Background Online Advertising Revenue Models Misc. Ad exchanges Advertising Setting CPM CPC CPA Sponsored Search Display Content Match
Advertising Setting Pick ads Ads Advertisers Ad Network Content • What do you show the user? • How does the user interact with the ad system? User Content Provider
Advertising Setting Sponsored Search Display Content Match
Advertising Setting Sponsored Search Display Content Match Pick ads
Advertising Setting • Graphical display ads • Mostly for brand awareness • Revenue model is typically CPM Sponsored Search Display Content Match
Advertising Setting Sponsored Search Display Content Match Content match ad
Advertising Setting Sponsored Search Display Content Match Text ads Pick ads Match ads to the content
Advertising Setting • The user intent is unclear • Revenue model is typically CPC • Query (webpage) is long and noisy Sponsored Search Display Content Match
Advertising Setting Sponsored Search Display Content Match Search Query Sponsored Search Ads
Advertising Setting Sponsored Search Display Content Match Pick ads Text ads Search Query Match ads to the query
Advertising Setting • User “declares” his/her intention • Click rates generally higher than for Content Match • Revenue model is typically CPC (recently some CPA) • Query is short and less noisy than Content Match Sponsored Search Display Content Match
Summary • Different revenue models • Depends on the goal of the advertiser campaign • Brand awareness • Display advertising • Pay per impression (CPM) • Attracting users to advertised product • Content Match, Sponsored Search • Pay per click (CPC), Pay per action (CPA)
Background Online Advertising Revenue Models Misc. Ad exchanges Advertising Setting CPM CPC CPA Sponsored Search Display Content Match
Unified Marketplace • Publishers, Ad-networks, advertisers participate together in a singe exchange • Publishers put impressions in the exchange; advertisers/ad-networks bid for it • CPM, CPC, CPA are all integrated into a single auction mechanism
Overview: The Open Exchange Bids $0.75 via Network… Bids $0.50 Bids $0.60 Ad.com AdSense Bids $0.65—WINS! Has ad impression to sell -- AUCTIONS … which becomes $0.45 bid Transparency and value
Unified scale: Expected CPM • Campaigns are CPC, CPA, CPM • They may all participate in an auction together • Converting to a common denomination is a challenge
Outline • Background on online advertising • The Fundamental Problem • Statistical sub-problems: • Description • Existing methods • Challenges
Outline • Background on online advertising • The Fundamental Problem • Display advertising • Sponsored Search and Content Match • Statistical sub-problems: • Description • Existing methods • Challenges
Does it work? • Lewis and Reiley, 2009. Retail Advertising Works! Yahoo! Technical Report • Controlled experiment assigning customers to treatment and control groups for a large retailer • Advertising significantly improved purchases (online and offline) • Good news! Main goal is brand awareness • Revenue model typically CPM, advertiser takes all the risk
Display adverting: Buyer and Seller • Advertiser (Buyer) • Buy ad space well in advance or in spot market • May buy from publisher who may guarantee or not • Typically, guaranteed contracts cost more, price higher • Publisher (seller) • Sell in advance (guaranteed) or sell in spot market
Display Advertising • Main goal of advertisers: Brand Awareness • Revenue Model: Primarily Cost per impression (CPM) • Traditional Advertising Model: • Ads are targeted at particular demographics (user characteristics) • GM ads on Y! autos shown to “males above 55” • Mortgage ad shown to “everybody on Y! Front page” • Book a slot well in advance • “2M impressions in Jan next year” • These future impressions must be guaranteed by the ad network
Display Advertising • Fundamental Problem: Guarantee impressions to advertisers • Predict Supply: • How many impressions will be available? • Demographics overlap • Predict Demand: • How much will advertisers want each demographic? Young US 2 1 4 3 2 2 1 Y! Mail Female
Display Advertising Fundamental Problem: Guarantee impressions to advertisers si xij dj • Predict Supply • Predict Demand • Find the optimal allocation • subject to supply and demand constraints Young US 2 1 4 3 2 2 1 Y! Mail Female
Display Advertising Fundamental Problem: Guarantee impressions to advertisers Predict Supply Predict Demand Find the optimal allocation, subject to constraints Optimal in terms of what objective function? Depends on the goal of the ad-network Advertisers don’t specify too many targets Dangerous for ad-networks to allow that (difficult to forecast) BUT they expect good inventory (campaign should result in good conversion rates)
Allocation through Optimization si supply demand xij dj • Optimal in terms of what objective function? • E.g. Maximize value of remaining inventory • Cherry-picks valuable inventory, saves it for later • Fairness • “Spreads the wealth” subject to constraints
Example Supply Pools Young US, Y, nFSupply = 2Price = 1 US Demand 2 1 4 3 US & Y(2) 2 2 US, Y, FSupply = 3Price = 5 1 Y! Mail Female Supply Pools How should we distribute impressions from the supply pools to satisfy this demand?
Cherry-picking:Fulfill demands at least cost Example (Cherry-picking) Supply Pools US, Y, nFSupply = 2Price = 1 Demand (2) US & Y(2) US, Y, FSupply = 3Price = 5 How should we distribute impressions from the supply pools to satisfy this demand?
Cherry-picking:Fulfill demands at least cost Fairness:Equitable distribution of available supply pools Example (Fairness) Supply Pools US, Y, nFSupply = 2Cost = 1 Demand (1) US & Y(2) (1) US, Y, FSupply = 3Cost = 5 How should we distribute impressions from the supply pools to satisfy this demand?
Display Advertising Fundamental Problem: Guarantee impressions to advertisers Predict Supply Predict Demand Find the optimal allocation, subject to constraints Pick the right objective function Further issues: Risk Management: Supply and demand forecasts should have both mean and variance Forecast aggregation: Forecasts may be needed over multiple resolutions, in time and in demographics Challenging time series problem Adapting system to external events
Display Advertising • Fundamental Problem: Guarantee impressions to advertisers • Predict Supply • Predict Demand • Find the optimal allocation, subject to constraints • Pick the right objective function • Forecasting accuracy is critical! • Overshoot under-delivery of impressions unhappy advertisers • Undershoot loss in revenue
Outline • Background on online advertising • The Fundamental Problem • Display advertising • Sponsored Search and Content Match • Statistical sub-problems: • Description • Existing methods • Challenges
Sponsored Search and Content Match • Given a query: • Select the top-k ads to be shown on the k slots to maximize total expected revenue • What is total expected revenue?
Example (Content Match) Ad Position 1 Ad Position 2 Ad Position 3
Reminder: Auction Mechanism • Revenue depends on type of auction • Generalized First-price: • CPC = bid on clicked ad • Generalized Second-price: • CPC = bid of ad below clicked ad (or the reserve price) • CPC could be modified by additional factors • Total expected revenue = revenue obtained in a given time window • [Optimal Auction Design in a Multi-Unit Environment: The Case of Sponsored Search Auctions] by Edelman+/2006 • [Internet Advertising and the Generalized Second Price Auction…] by Edelman+/2006