Fine-Tuning the eBay Technical Infrastructure, Part 2: Our Q1 Digital Service Efficiency Results

As discussed in a previous post, earlier this year we unveiled the Digital Service Efficiency (DSE) methodology, our miles-per-gallon (MPG) equivalent for viewing the productivity and efficiency of our technical infrastructure across four key areas: performance, cost, environmental impact, and revenue. The goal of releasing DSE was to provide a transparent view of how the eBay engine is performing, as well as spark an industry dialogue between companies, big and small, about how they use their technical infrastructure and the impact it’s having on their business and the planet. In the past month, we’ve been excited to see – and participate in – the resulting dialogue and conversation.

When we shared DSE externally for the first time, we also set a number of performance goals for 2013 and committed to disclosing updates on our progress on a quarterly basis. Today, we’re pleased to share our first such quarterly update with year-over-year comparisons and analysis. This post provides highlights of our findings as well as links to the DSE dashboard and other details.


Q1 metrics summary

Here’s where we stand on the progress toward 2013 performance and efficiency goals:

  • Our transactions per kWh increased 18% year over year. The growth of eBay Marketplaces and continued focus on driving efficiencies have contributed to this increase.
  • Our cost per transaction decreased by 23% in Q1 alone, already exceeding our initial goal.
  • Our carbon per transaction showed a net decrease of 7% for the quarter. As we’re still on track for our Utah Bloom fuel cell installation to go live this summer, we expect this number to continue to decrease and contribute significantly to our 10% carbon reduction goal for the year, even with our projected business growth.

Recognizing that our dynamic infrastructure changes each quarter, we’re confident that we’re on track for our 10% net gain across performance, cost, and environmental impact for the year.


We’ve seen a few other interesting trends as well:

The New eBay: Over the past year we’ve added numerous new features to our site. Last fall, we rolled out our feed technology, which makes the shopping experience on more personal to each of our individual users. On the backend, with this curated site personalization, we’ve seen a jump in our transaction URLs as the eBay feed technology increases infrastructure utilization. This is one example of our customers’ site use driving a more productive work engine.

Continued Growth and Efficiency: As you can see on the dashboard, we had a significant spike in the number of physical servers powering – a 37% increase year over year. The rise is in direct response to increased customer demand and personalization for our users. And while we added a significant number of new servers, we were able to limit our increase in power consumption to just 16% (2.69 MW). Compared to the first quarter of last year, we’ve reduced the power consumed by an average of 63 watts per server; this is a direct result of our efforts to run more energy-efficient servers and facilities.

Running a Cleaner Engine: As eBay aspires to be the leading global engine for greener commerce, we’re continually focused on integrating cleaner and renewable energy into our portfolio. In March, our Salt Lake City data center’s solar array came online and though it’s relatively small, it increased our owned clean energy powering by 0.17%. Our active projects with fuel cells and renewable energy sourcing will continue to increase this value through the year.

Continuing to Refine Our Approach

When we first announced DSE, one of our top priorities was continued transparency into our metrics, calculations, and lessons learned. Along those lines, the greater transparency has also sparked internal conversations at eBay about how our server pools are categorized.

We organize each server into one of three categories: “buy,” “sell,” or “shared.” “Buy” and “sell” serve the pages and APIs directly for customer traffic, which count as our transactions (URLs); “shared” is the backend support equipment, which does not receive external traffic.

When we released the 2012 DSE numbers we reported 7.3 trillion URLs or transactions in the “buy” and “sell” groups. As we rolled up the Q1 2013 numbers, we found that some internally facing servers were grouped into “buy” and “sell.” We moved them to the appropriate “shared” group. While this did not change overall server counts or power consumption, it did decrease the 2012 transactions count coming from the external servers to 4.3 trillion. We also moved some server groups from “sell” to “buy” to be more consistent with our business model (unlike before, when “buy” and “sell” were relatively more equal). We felt it was important to stay strict with our methodology, and so we have retroactively updated the 2012 baseline numbers to ensure that our year-over-year results were standard and consistent.

Based on lessons learned in the Q1 2013 work, we’ve fine-tuned our methodology as follows:

  1. We’ll look only at those server pools that receive external web traffic in order to ensure that we’re accurately speaking to the year-over-year comparisons for “buy” and “sell” – all other server pools not receiving external web traffic will be considered “shared.”
  2. We’re now measuring Revenue per MW hour (as opposed to Revenue per MW), as this metric represents total consumption per quarter and year instead of quarterly averages. Likewise, we’ve decided to measure CO2e per MW hour instead of CO2e per MW.


With the Q1 2013 results under our belt, we’re happy with the progress we’ve made to fine-tune our technical infrastructure and the DSE metric. We still have more to do, though, and we’ll be sure to keep you updated along the way.

You can find the full Q1 2013 DSE results at, and click through the dashboard yourself to see the full cost, performance, and environmental impact of our customer “buy” and “sell” transactions.

Have a question or comment? Leave a note in the comments below or email and we’ll be sure to get back to you.

– Sri Shivananda, Vice President of Platform, Infrastructure and Engineering Systems, eBay Inc.