Author | Tien

Click here to register and download the most recent CSE Rankings from the previous quarter.

To revisit, the purpose of this study is to compare the major comparison shopping engines (or CSE’s) and see how they rank in terms of size/volume, cost, return rates, and overall service using in-house data using the following categories:

  • overall traffic driven
  • average amount of revenue generated
  • COS (Cost of Sale) % or return on spend
  • average CPC rates
  • responsiveness rate among the engines
  • quality of merchant tools

For those who can’t wait until the end, this was how the engines ranked this time around:


Once again Google finished on top based on our point system, followed very closely by the next tier of comparison shopping engines (see the end for final scores).

Bing’s Cashback finished near the middle of the pack with its CPA (cost per acquisition) model, and the rest falling into place quite closely as well.


Our comparison shopping report involved accumulating data from Q2 of 2009 from a select number of our own clients focusing in soft goods (non-tech) across a wide array of industries, sizes, and product lines in order to reduce engine bias as much as possible.

It’s important to note that these are what we’ve deemed in our experience the top ten performing comparison shopping engines that our clients are listed on, out of literally hundreds of different engines out there.

Google Base, as it’s referred to in this study, is known to many as “Google Product Search”, “Google Shopping”, and originally as “Froogle”, but all refer to the same product.

Results will likely vary among individual merchants across specific engines, but this accumulative study should give a good idea of how the engines compare to each other.

Overall this should give merchants who aren’t yet on the engines, or those already on and looking to expand their campaigns, a decent idea of what to expect with comparison shopping.

Traffic (average clicks per month)


While getting a lot of traffic is not the primary goal of a (good) comparison shopping campaign, it’s desirable in that one can always cut products in order to reduce traffic and costs–whereas it’s much more difficult to force traffic onto a campaign on a smaller shopping engine.

Our “big 4” definition of paid shopping engines is primarily derived here, as Shopzilla, Nextag,, and Pricegrabber are the primary traffic drivers to our merchants’ sites while the rest still account for a reasonable amount of traffic as well.

Differences worth noting from our last study include Shopzilla shifting down from #1 to #2, though remaining very close, and Google Product Search gaining traction and jumping from our #5 spot to #3.

Revenue (average per month)


Next we look at average revenue generated by each comparison shopping engine. While there’s a strong correlation between traffic that was brought in, since more traffic in theory should lead to more conversions, in our study Nextag pulls ahead of the pack due to their strong abilities to drive quality traffic to our merchants’ sites–but again each engine has the ability to drive a decent amount of revenue to each site.

Again, compared to our last study, Google Product Search has leaped to very near the top, being right in the middle of the main CPC-model engines.



COS % is a metric defined as spend/revenue, and gives merchants an idea of the return that they’re getting for every dollar that they’re spending. Since all traffic generated off of Google Base is free, it tops our list here since all revenue comes at zero cost–while Microsoft’s Cashback was slightly behind it as it gives merchants the ability to set their own revenue share percentage (generally we find a range of 5-10% to be a good range to generate sales while keeping costs low–but enough to create incentive to buy).

For many merchants this is the most important metric in a campaign as they generally seek to maximize the return on their spend–and as a result we’ve doubled the importance of this measurement within our study for our final rankings.

Average CPC


At the top here are Google Base and Microsoft’s Cashback since their traffic is essentially “free”, while Become and Smarter, being two of the smaller shopping engines they have lower rates in order to allow them to compete with the larger engines since there is a higher demand in order to be listed on them.

Responsiveness Rating (ranking from 1-10, 1 being best)











As a merchant it’s very important to have good responsiveness times and feedback from the engines in order to ensure that your campaign is going smoothly. As a full service management company, our account managers are constantly working with the various engines via e-mail/phone and have rated each of the engines in terms of their overall levels of responsiveness. tops comparison shopping list here due to their unmatched responsiveness and service levels, while Google Base is at the bottom this time due to their lack of having any true support system. You get what you pay for though right?

Merchant Tools
(ranking from 1-10, 1 being best)











Finally we’ve ranked each comparison shopping engine by the tools that they have in order to help the merchants run a successful campaign.

For this study, we used Google Analytics for Google Product Search, which is a highly comprehensive tool which allows for custom reporting at all sorts of levels, and provides breakdowns that none of the shopping engines offer. As a bonus, one can implement Google Analytics to track any of their comparison shopping campaigns.

We’ve also found that the larger engines generally offer a great tool set for merchants to work with, and in figuring out exactly where their money is being spent.

Important features that we find most valuable include SKU/category level reporting, bidding systems, and overall user friendliness.


In the end we ranked each comparison shopping engine from each of our metrics from 1-10 and assigning a point value for each category (higher being better).

We doubled the COS % value making that out of a possible 20 points, and weighted traffic + revenue as 1.5 each for a maximum of 15, summed it up, and got the following:

Engine Traffic Revenue Cos % Avg.
Merchant Tools Total
Google Base 12 12 20 10 1 10 65
Nextag 15 15 12 4 7 7 60
Shopzilla 13.5 13.5 10 5 8 9 59
PriceGrabber 10.5 10.5 16 3 9 8 57
Shopping 9 9 14 2 3 6 43
Cashback 1.5 1.5 18 9 4 2 36
Become 3 6 2 7 10 5 33
4.5 4.5 8 6 5 4 32
Smarter 6 3 4 8 6 3 30
Yahoo 7.5 7.5 6 1 2 1 25

(click on each column header to sort)

Once again, with its cost-free structure and highly regarded Google Analytics tool, Google Base tops our list of shopping engines, and see no reason at all why a merchant should not be listed on there.

Numbers two through 4 were extremely close in the race, though generally we recommend all our merchants list on the “big-4” paid engines in order to diversity themselves among all engines.

Final Thoughts

There weren’t many surprises or changes to this study this time around.

As with the previous comparison shopping report, our goal was to find as non-biased a way to measure the effectiveness of all the shopping engines, and our final rankings certainly reflect our personal opinions when it comes to the shopping engines.

Google Product Search is an absolute no-brainer to be listed on, while Nextag, Pricegrabber, Shopzilla, and are tremendous options to gain exposure on–so long as they keep a close eye on their campaigns.

There’s also no reason for a merchant not to be listed on Microsoft’s Bing Cashback, as its CPA model makes for effortless management, and its recent growth and relaunch of Bing itself should only help provide further opportunity for a merchant to be successful on there.

The final tier of engines included in our comparison shopping report, while not as major as traffic drivers to a merchant’s site, are also important to be listed on as complementary to the larger ones, and are especially appealing due to their generally lower cost per click rates.

Again we should note that while there are many dozens of shopping engines out there, and while each may be unique to listing specific products in particular categories, what we deem as the top 10 is a good start for any merchant looking to go on the engines, or in expanding their campaigns.

If you want to check out the comparison shopping engines for themselves, take a look at their sites here: