The Revenue Champion of L2s
Over the past 180 days Coinbase’s Layer-2, Base, has averaged $185 k in daily profit, more than triple second-place Arbitrum ($55 k) and greater than the combined haul of the next fourteen roll-ups. The secret is not volume alone; it is how transactions are ordered and priced.

A Two-Variable Auction for Block Space
Base’s sequencer ranks every incoming transaction by:

1. Submission time (latency)

2. Economic incentive (priority fee per unit of gas)

Think of it like a courier truck: parcels are loaded in arrival order, but anyone can pay an express surcharge to jump the queue. The sequencer therefore runs a per-gas auction, identical in spirit to Ethereum’s EIP-1559, balancing speed and spend.

The Logistics Analogy
Imagine a delivery truck with limited cargo room:

• Big box: $50 base fare + $10 tip, half the truck.

• Small box: $20 base fare + $10 tip, tiny footprint.
  The driver—seeking tip-per-cubic-inch—chooses the small box. Base’s sequencer does the same, maximising priority fee per unit of gas, not total fee.

Base vs. Arbitrum: Two Philosophies

• Base: live auction—users bid per transaction for immediate inclusion. Revenue scales with marginal willingness to pay.

• Arbitrum: strict first-come-first-served. Users race on latency, not price; revenue only grows with aggregate demand.
  Arbitrum’s new Timeboost lane adds an express track, but the bid is a blind, fixed fee for a future time-window, making it predictive rather than reactive—less efficient at capturing sudden high-value trades.

Where the Money Comes From
Base’s fees have three components:

1. L1 cost (posting calldata/blobs to Ethereum) – slashed by EIP-4844.

2. Base fee (mandatory, dynamic).

3. Priority fee (optional “tip”).

86 % of Base’s daily profit—$156 k—comes from priority fees.

• Slot #1 in each block alone yields 30–45 % of daily profit.

• Top 10 slots routinely account for 50–80 %.
  A mere 250 addresses supply 65 % of all priority fees; the single biggest tipper has paid $1.99 m over the past year.

Flashblocks & Shifting Slots
After the Flashblocks upgrade on 16 July, high-priority trades began landing in lower slots, diluting the share from slot #1. Yet total revenue stayed robust—evidence that more participants are bidding, not that value is vanishing.

Bottom Line
Base monetises every millisecond of urgency. By letting users pay for exact placement, it turns block space into a real-time marketplace, something most roll-ups have yet to replicate.