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Queue Distribution

A Queue is a first-come, first-served waiting line that manages high demand by giving access to consumers in the order they joined. Queues are ideal for product launches where fairness means “first in line gets access first.”

How Queues Work

When consumers join a queue, they’re assigned a position and wait for their turn:
┌────────────────────────────────────────────────────────────────────┐
│                         THE QUEUE FLOW                              │
├────────────────────────────────────────────────────────────────────┤
│                                                                    │
│    Consumers join and wait in line                                 │
│           │                                                        │
│           ▼                                                        │
│    ┌──────────────────────────────────────────┐                   │
│    │ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ │ ● │           │                   │
│    │ Back of queue              │Front│  →  Checkout access        │
│    └──────────────────────────────────────────┘                   │
│           │                        │                               │
│           │                        │                               │
│      New consumers            Consumers get                        │
│      join here               access at your                        │
│                              configured rate                       │
│                                    │                               │
│                                    ▼                               │
│                              Complete purchase                     │
│                              (time-limited window)                 │
│                                                                    │
└────────────────────────────────────────────────────────────────────┘

The Consumer Experience

  1. Join — Consumer enters the queue and receives a position number
  2. Wait — Position updates in real time as the line moves forward
  3. Get access — When they reach the front, they’re notified they can checkout
  4. Complete purchase — Limited time window to finish their purchase

Consumer Journey

┌─────────────────────────────────────────────────────────────────┐
│                    QUEUE CONSUMER JOURNEY                       │
├─────────────────────────────────────────────────────────────────┤
│                                                                 │
│  ┌─────────────┐                                               │
│  │ Not in Line │                                               │
│  └──────┬──────┘                                               │
│         │ Join queue                                           │
│         ▼                                                      │
│  ┌─────────────┐                                               │
│  │  In Queue   │  (watching position)                          │
│  └──────┬──────┘                                               │
│         │ Reach the front                                      │
│         ▼                                                      │
│  ┌─────────────┐                                               │
│  │   Access    │  (checkout available)                         │
│  │   Granted   │                                               │
│  └──────┬──────┘                                               │
│         │ Complete purchase                                    │
│         ▼                                                      │
│  ┌─────────────┐                                               │
│  │  Complete   │                                               │
│  └─────────────┘                                               │
│                                                                 │
└─────────────────────────────────────────────────────────────────┘

When to Use Queues

ScenarioWhy Queue Works
Product launchesFirst in line gets access first
Event ticketingOrderly flow prevents site overload
Flash salesManages traffic while rewarding early arrivers
Limited inventoryEnsures fair, ordered access to scarce items
High-demand dropsPrevents site crashes by throttling access

Configuration Options

Admission Rate

How many consumers per minute receive access to checkout.
RateResult
50/minuteAbout 1 consumer per second gets access
100/minuteAbout 1.7 consumers per second
200/minuteAbout 3.3 consumers per second
Tips for setting admission rate:
  • Match your checkout system’s capacity
  • Too high = checkout overwhelmed
  • Too low = unnecessary waiting

Queue Capacity

Maximum consumers allowed in the queue at once.
  • Set a limit when you want to manage server load or set expectations
  • Leave unlimited when you want to accept everyone and let them wait

Total Admissions

Maximum total consumers who can receive access.
  • Set a limit when inventory is fixed (e.g., 500 items available)
  • Leave unlimited when you want continuous access until closing time

Access Window Duration

How long consumers have to complete checkout after receiving access.
DurationBest for
5-10 minutesSimple purchases, saved payment methods
15-20 minutesMultiple items, entering payment details
30 minutesComplex purchases, high-value items

What Consumers See

While Waiting

  • Their current position in line
  • Estimated wait time
  • Real-time updates as the line moves

When It’s Their Turn

  • Notification that they can proceed
  • Time remaining to complete purchase
  • Clear call-to-action to checkout

If They Take Too Long

  • Warning as time runs low
  • Notification when access expires
  • Option to rejoin (if the queue is still open)

Configuration Examples

Product Launch

High-demand sneaker drop with limited inventory:
Queue Settings:
├── Admission rate: 100/minute
├── Total admissions: 500 (matches inventory)
├── Access window: 10 minutes
└── Allow guests: Yes

Event Ticketing

Concert tickets going on sale:
Queue Settings:
├── Admission rate: 200/minute (handle high volume)
├── Queue capacity: 50,000 (manage expectations)
├── Access window: 15 minutes (time to select seats)
└── Allow guests: No (need account for tickets)

Flash Sale

Time-limited sale with steady access:
Queue Settings:
├── Open time: 9:00 AM
├── Close time: 12:00 PM
├── Admission rate: 50/minute
├── Total admissions: Unlimited
└── Access window: 5 minutes

Why Consumers Might Not Get In

ReasonWhat HappenedConsumer Message
Queue fullQueue reached capacity”Queue is at capacity. Try again later.”
Queue closedOutside open hours”This queue is currently closed.”
Already purchasedHit their order limit”You’ve already purchased the maximum allowed.”
Access expiredTook too long at checkout”Your checkout window has expired.”

Best Practices

1. Set the Right Admission Rate

Match your checkout capacity. If your checkout can handle 2 purchases per second, an admission rate of 100/minute leaves headroom for abandoned carts.

2. Configure Appropriate Time Windows

Balance urgency with fairness:
  • Too short = frustrated consumers who can’t complete in time
  • Too long = people holding spots they won’t use

3. Communicate Clearly

Show consumers:
  • Their position and estimated wait
  • What happens when it’s their turn
  • How long they’ll have to complete

4. Handle Capacity Gracefully

When the queue fills up:
  • Show a clear message about capacity
  • Offer a waitlist as an alternative
  • Give expected reopening times

Common Patterns

Rolling Queue

Continuously accepts and admits consumers over a longer period:
  • Open for an extended time (days or weeks)
  • Steady admission rate
  • No total admission limit
  • Limited queue capacity to manage expectations

Burst Queue

Handles launch-day spikes:
  • Short open window (30 minutes to a few hours)
  • Higher admission rate
  • Set total admissions to match inventory
  • Unlimited queue capacity to accept everyone

Recycling Expired Spots

When consumers don’t complete checkout:
  • Their spot can be recycled
  • Next person in line gets access sooner
  • Helps ensure all inventory sells