
How I increased my conversion rate 56% on Shopify. Hint: Image Optimization - j0rd
https://medium.com/@j0rd/an-open-letter-to-shopify-a-feature-worth-supporting-7f7334345188?hello=bar
======
j0rd
Some Shopify sites I just tossed through webpagetest.org, all of which are
case studies from the homepage or blog.

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smartnora.com

7,370.8 KB total in images, target size = 1,387.2 KB - potential savings =
5,983.6 KB

[http://www.webpagetest.org/result/160307_Z2_VMS/1/performanc...](http://www.webpagetest.org/result/160307_Z2_VMS/1/performance_optimization/#compress_images)

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muttonheadstore.com

3,739.8 KB total in images, target size = 1,780.8 KB, potential savings =
1,959.0 KB

[http://www.webpagetest.org/result/160307_GE_TYT/1/performanc...](http://www.webpagetest.org/result/160307_GE_TYT/1/performance_optimization/#compress_images)

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nutbutternation.com

1,150.6 KB total in images, target size = 555.7 KB - potential savings = 594.9
KB

[http://www.webpagetest.org/result/160307_KQ_VNN/1/performanc...](http://www.webpagetest.org/result/160307_KQ_VNN/1/performance_optimization/#compress_images)

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d4n3
It seems like you're comparing current conversion rates vs. past conversion
rates.. Did you try AB testing this side by side? It's not necessarily only
the effect of image optimisation, could be just organic growth of your site?

~~~
j0rd
I'm personally not going to A/B test larger webpage downloads for my
customers.

Smaller is better & faster. There's no noticeable difference in image quality.

So my A/B test is 4 months before vs. 4 months after. This is not a small
sample size. It's around 500k uniques on each end. 3M+ page views on each end.

I've also broken & analyzed the traffic down by channel, new vs return, and
any other way I can to attempt to remove any false positives. From all the
data, the large increase in conversion was because of this particular change.

I have been aware of "holiday shopping bias" around nov / dec, but January is
normally a very shitty month for conversions. January / Feb our conversion was
higher than any previous month before this as well.

This is actually why I've waited to Feb to really solidify the results in my
own mind. And that's why there's 4 months of data to back it up. Every day
since the change, being better than before.

I don't need to A/B test this one. The savings on my homepage was 4MB. We're
not talking small bytes here. This is a major issue with regards to anyone
using Shopify.

See if you can guess which month the change happened on this chart:
[http://i.imgur.com/S95EX9Q.png](http://i.imgur.com/S95EX9Q.png)

Because I can see it.

~~~
Cpoll
> I'm personally not going to A/B test larger webpage downloads for my
> customers.

That's very sensible. But then you can't state that smaller images alone
increased your conversion rate by 56%. Maybe your products are just more
Winter-appropriate? If you can't control for confounding factors, you can't
make a strong conclusion.

...On the other hand, in a contrived example, one could imagine smaller images
could increase conversion rate by 1000% (if it cuts several minutes off the
process; a website that takes 5 minutes to load will get no customers).

What I would like to see is an analysis of how much faster the shopping
experience is post-compression. Perhaps for some of those edge cases (like
your 250+ item shoppers)

~~~
j0rd
Agreed, don't take 56% as fully being attributed to smaller page loads.

In two weeks after the change with out any other changes to traffic or
anything else, the improvement was 38%.

I've talked about my findings with more caution here:
[https://ecommerce.shopify.com/c/ecommerce-
discussion/t/shopi...](https://ecommerce.shopify.com/c/ecommerce-
discussion/t/shopify-image-quality-optimization-round-2-with-
stats-38-improvement-304813)

My worst day after this change, was better than my best day previous to this
change. Thousands of visitors.

This trend has continued for 4 months after the change. Hundreds of thousands
of visitors.

I'm the only dev on this project and I know what changes day to day.

Can full 56% be attributed? No. I added opt-in monster with 10% & 20% (A/B)
discount in Feb which boosted conversions. 10% actually out performs 20%. Go
figure.

Can more than 0% be attributed to smaller images. Yes. So I'd say this change
helped between 0% and 56%. Either way, it's statistically significant.

4MB savings on homepage going to save you from a shit tonne of bounces and
help move more people towards that checkout page.

------
j0rd
If anyone has any questions, concerns or comments, feel free to ask. I'll be
here to answer for next couple hours.

