The Best Comparison Shopping Engine

Author | Tien

Choosing which comparison shopping engine (also sometimes called a shopping channel) to sell your products on is difficult. A simple search for “best comparison shopping engine” on Google has over 9 million results.

For online sellers, it’s important to determine which comparison shopping engine will give them the highest amount of traffic, the most sales, or the lowest cost of sale.

To answer the question “What is the best comparison shopping engine?” we study performance on each of the comparison engines and rank them based on:

  • Traffic
  • Revenue
  • Conversion rate
  • Cost of sale
  • Shopping Engine Responsiveness (gives retailers, marketers and agencies an indication of how helpful each data feed marketing channel is with merchant support)
  • Merchant Tools (gives retailers, marketers and agencies an indication of how easy each data feed marketing platform is to use)

How We Rank The Comparison Shopping Engines

Please note that the rankings below are based on CPC Strategy clients results on the CSEs. That means how we’re managing the comparison shopping engines directly affects the numbers we report, and doesn’t necessarily reflect the results you’ll get if you were to list on them.

Here’s how we manage them:

– ROI is a focus. Retailers have razor thin margins and we’re expected to hit them, so we cut fat wherever possible.

– Our product feeds follow best practices and are custom-built.

– Our Data Analysts adjust bids on a daily basis, which effects all reporting variables. 

– Numbers and strategy vary across categories, so  for certain category retailers, COS numbers are lower or higher.

Best Comparison Shopping Engine: Q2 2013

To see which comparison shopping engine is the best investment for online merchants this quarter Q2 2013, check out the comparison shopping report below.

Best Comparison Shopping Engine: Conversion Rate

Best Comparison Shopping, Conversion Rate

Google Product Listing Ads and Bing had very close conversion rates this quarter, as  the first and second highest converting comparison shopping engines overall.

Conversion rate increased across the board for Q2 2013 with the highest converting engine Google increasing from 3.3% to 3.41%. And the lowest converting engine Pricegrabber from 1.6% in Q1 2013 to 1.84% in Q2.

Conversion Rate Changes From Q1 2013:

  • Both Bing and Pronto’s conversion rate increased significantly this quarter. Bing moving from the fourth highest converting engine in Q1 2-13 (2.2%) to the second highest converting comparison engine in Q2 (3.33%).
  • Pronto increased conversion rates from 1.8% in Q1 2013 (8th highest converting engine) to 3% in Q2, as the third highest converting comparison engine.
  • Amazon’s conversion rate decreased from Q1 2013 from the second highest converting shopping engine (2.7%) to the seventh highest converting engine in (2. 12%).

Google Note: Like the previous quarter, we separated free and paid Google traffic to demonstrate the differences between overall traffic and performance for both paid Google Shopping and free Google traffic.

Best Comparison Shopping Engine: Cost Of Sale (COS)

Best Comparison Shopping, Cost of sale

Cost of Sale increased for the majority of comparison engine from Q1 2013 to Q2, However, no  individual cost of sale increases were drastic.

Cost of Sale Changes From Q1 2013:

  • Become’s cost of sale increased from Q1 (25%) to Q2 2013 (28.10%), causing the engine to become the highest in cost of sale.
  • Shopzilla’s cost of sale decreased from Q1 2013 (27%) to Q2 (22.59%) bumping the engine from the highest cost of sale to the third highest.
  • One of the most significant cost of sale changes this quarter belongs to Amazon, which went from a 15% COS in Q1 2013, to a 20.45% COS in Q2.

Products We’re Sending To Shopping Engines

As we mentioned above, since our data is based on CPC clients, the number of products we’re sending to each comparison engine affects the other performance metrics.

What the percentages represent is how much of the total feed we’re sending on average to each respective CSE.

e.g. a year ago we were sending on average 38.42% of a merchant’s total products to Amazon, and currently we’re sending on average 15.73% of their products in order to maintain a high ROI.

Comparison Shopping Engine

Q2 2012 Products Sending (%)

Q2 2013 Products Sending (%)

# of Products Change (%)

Google  100.00% 100.00% 100.00%
Pricegrabber 60.94% 51.49% -15.50%
Shopzilla 54.68% 50.96% -6.82%
Pronto 37.17% 49.17% 32.28%
Become 34.94% 24.39% -30.20%
Nextag  32.81% 17.05% -48.03%
Amazon  38.42% 15.73% -59.07%
Shopping 34.69% 14.40% -58.47%

A few things to note about the above chart:

  • Google is the baseline here since we will tend to send all of a merchant's products since it is the highest performing one.
  • Pricegrabber + Shopzilla are in 2nd and 3rd place due to the ability to make bid changes within the login, often at a CPC rate lower than the "minimum" bids
  • Become/Pronto are generally lower volume so we try to get as much exposure on there as possible
  • will be the CSEs that we will generally only send a merchant's top performing SKUs to ensure the campaigns meet our clients' ROI goals


Best Comparison Shopping Engine: Traffic

Best Comparison Shopping, traffic


Since Google's transition to Product Listing Ads back in July of 2012, lower COS and high conversion rate for Product Listing Ads have made it a good engine to help maintain ROI goals. Consequently, account managers use Google Shopping as a large part of their management strategy- pushing more traffic through Product Listing Ads and often limiting exposure on the other channels. These results are based on CPC client data, which reflects the shift in managment. 

Traffic Changes From Q1 2013:

  • moved from the second highest traffic generating engine in Q1 (50.81) to the third position for Q2 2013 .
  • Pricegrabber decreased in overall traffic following Q1 (50.72), moving from the third highest traffic generating engine to the fourth.
  • While Nextag was the fifth highest traffic generating engine in Q2 (39.96), the engine significantly picked up traffic  for this quarter, coming in behind Google.

Here is a breakdown of the traffic data for Q2 2013 by percentage: 

Comparison Shopping Engine

Traffic Increase or Decrease (%)

Google Product Listing Ads 40.28%
Nextag 32.36%
Amazon -6.73%
Shopping -10.19%
Bing -16.52%
Pricegrabber -20.72%
Shopzilla -31.68%
Google (Free) -31.75%
Become -49.14%


Best Comparison Shopping Engine: Revenue

Best Comparison Shopping, Revenue


For Q1 2013, Google incurred the largest revenue of the comparison shopping engines (100), with Amazon coming behind with a little over half of Google's revenue (57).

Keep in mind that these numbers are based on CPC Strategy client results. Google's  low COS and high conversion rate for Product Listing Ads make it a good choice for accounts, so revenue numbers are higher for Google Shopping and lower for other CSEs based on account management strategy. 

This quarter, the gap between Google and the second highest traffic engine is much larger than we've seen in any previous quarters.

Revenue Changes From Q1 2013:

  • Amazon's revenue decreased from Q1 2013 (57) to Q2 (19.85), causing it to get bumped from second place.
  • Nextag's overall revenue actually decreased from Q1 2013 (38) to Q2 (30.88), however it beat out the other CSEs for second highest revenue generated.
  • Revenue for all of the comparison shopping engines saw a decrease from Q1 2013 to Q2.

Here is a breakdown of the Q2 2013 revenue data by percentage:

Comparison Shopping Engine

Revenue Increase or Decrease (%)

Bing 81.46%
Google Product Listing Ads 65.76%
Nextag 33.09%
Shopping 8.63%
Google (Free) 0.38%
Shopzilla -13.55%
Pricegrabber -14.49%
Amazon -43.06%
Become  -52.10%


Best Comparison Shopping Engine: Responsiveness Rating

Comparison shopping engine responsiveness is rated on a scale of 1-9, 1 being the most responsive comparison engine, and 9 being the least responsive.

Comparison Shopping Engine Responsiveness

1. Become
2. Pricegrabber
3. Nextag
4. Shopping
5. Shopzilla
6. Pronto
7. Amazon Product Ads
8. Bing
9. Google 

The Account Managers at CPC consult with the shopping engines, and support daily in order to troubleshoot campaign issues and optimize strategy. They  know first hand which engines are quickest to respond and how helpful those repsonses are.

In general, and with AdWords Support, persistence pays off.

Best Comparison Shopping Engine: Merchant Tools

Comparison shopping engine merchant tools are rated on a scale of 1-9, 1 being the shopping engine with the best merchant tools, and 9 being the comparison engine with the least helpful tools.

Comparison Shopping Engine Merchant Tools

1. Google 
2. Pricegrabber
3. Shopzilla
4. Nextag
5. Become
7. Pronto
8. Amazon Product Ads
9. Bing 

The Comparison Shopping Report Q2 2013: Top 10 CSEs

The top comparison shopping engines are rated based on the number of products we're sending for each engine compared to the previous year and Google.

Comparison Shopping Engine Traffic Revenue Conversion Rate (%) Cost of Sale (COS) Comparison Engine Responsiveness Comparison Engine Tools Total
Google Product Listing Ads  15.0 15.0 15.0 16.0 1.0 9.0 71.0
Nextag  13.5 13.5 10.5 12.0 7.0 6.0 62.5
Pricegrabber 9.0 9.0 1.5 14.0 8.0 8.0 49.5
Free Google  4.5 4.5 7.5 20.0 1.0 9.0 46.5
Amazon  10.5 12.0 6.0 10.0 3.0 2.0 43.5
Shopping 12.0 10.5 3.0 8.0 6.0 4.0 43.5
Bing  3.0 3.0 13.5 20.0 2.0 1.0 42.5
Shopzilla  7.5 7.5 9.0 6.0 5.0 7.0 42.0
Become 6.0 6.0 4.5 2.0 9.0 5.0 32.5
Pronto 1.5 1.5 12.0 4.0 4.0 30 26.0



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