TL;DR: For a Shopify store doing 3,000 orders a month, the same “how did you hear about us?” survey costs $25 a month on Grapevine, $119 on KnoCommerce, $149 on Fairing, and $399 on Zigpoll. None of them slows your product pages if the survey stays on the Thank you page. Pick by the integrations you need, not by the feature grid.
I asked ChatGPT which of these four a $3M Shopify brand should buy. It priced KnoCommerce as “$19 to $299” and, on speed, said of one vendor’s script size: “This is a vendor claim, not an independent performance benchmark.”
That is the whole problem with this category. Every comparison page ranking for “Fairing vs KnoCommerce” is written by Fairing, KnoCommerce, or a directory that copies their pricing tables. So on October 3, 2026, I priced all four from the live Shopify App Store listings and vendor pricing pages, then checked the speed side against my own App Speed Index.
Download the Post-Purchase Survey Cost and Setup Sheet (PDF)
Why does a post-purchase survey matter for my ad spend?
A post-purchase survey asks a buyer one question on the Thank you page: where did you first hear about us? The answer is self-reported, so it is not causal proof. It is still the only attribution source that does not depend on a pixel firing or a cookie surviving.
- Meta and TikTok each claim credit for the same order, and only a buyer’s answer breaks the tie.
- Podcasts, creators, and word of mouth rarely leave a click, so pixels undercount them.
- A $3M brand moving even 10% of a $60,000 monthly ad budget on better data is $6,000 a month.
I treat the survey as a tiebreaker next to the ad platforms and my profit analytics dashboard, never as a replacement.
What does each post-purchase survey app actually cost?
The four apps bill on four different meters. Fairing charges by orders, Zigpoll by survey responses, KnoCommerce by live surveys and integrations, and Grapevine charges one flat price. Here is the list pricing, monthly billing, as published on October 3, 2026.
| App | Billing meter | Entry paid plan | Free option | Rating |
|---|---|---|---|---|
| Fairing | Orders a month | $49 (201 to 500 orders) | Free up to 200 orders | 5.0 (196 reviews) |
| KnoCommerce | Live surveys + integrations | $19 Starter | 7-day trial | 4.9 (117 reviews) |
| Zigpoll | Survey responses | $39 (200 responses) | Free up to 50 responses | 5.0 (554 reviews) |
| Grapevine | Flat | $25, unlimited responses | 14-day trial | 5.0 (228 reviews) |
The cheap entry prices hide two traps. KnoCommerce’s $19 Starter plan lists 0 integrations and one survey with three questions. If you want answers flowing into Klaviyo or Triple Whale, you are on Analyst at $119.
Zigpoll’s App Store listing bills four plans: Lite (50 responses), Standard ($39, 200), Advanced ($129, 600), and Premier ($399, unlimited). Its own pricing page also shows Growth and Scale tiers at 1,000 and 2,000 responses, but the App Store listing does not price them, so I priced from what Shopify bills.
Fairing vs KnoCommerce vs Zigpoll vs Grapevine at 1,000, 3,000 and 10,000 orders
This is the table none of the vendor pages will show you, because each one wins a different row. I priced the plan a normal ad-driven store would need: integrations on, one attribution survey live.
| Orders a month | Grapevine | KnoCommerce (Analyst) | Fairing | Zigpoll |
|---|---|---|---|---|
| 1,000 | $25 | $119 | $99 | $129 (Advanced) |
| 3,000 | $25 | $119 | $149 | $399 (Premier) |
| 10,000 | $25 | $119 | $249 | $399 (Premier) |
| Yearly at 3,000 | $300 | $1,428 | $1,788 | $4,788 |
The Zigpoll jump needs one line of math. Zigpoll’s own blog says its customers see a 40%+ response rate on post-purchase pages. At 3,000 orders that is about 1,200 responses, double the 600 that Advanced allows. Advanced only covers 3,000 orders if fewer than 1 in 5 buyers answer.
Fairing climbs in steps. The Fairing pricing slider runs $149 up to 5,000 orders, $199 up to 7,500, $249 up to 10,000, $349 up to 15,000, and custom above 30,000.
Two discounts change the yearly line. Zigpoll Premier is $3,588 a year on annual billing, and KnoCommerce advertises 20% or more off annual plans. Ask for both before you compare.
Do post-purchase survey apps slow down a Shopify store?
Not when they run where they are meant to run. On the Thank you and Order status pages, a survey built as a checkout or customer account UI extension stays out of your theme entirely. Shopify’s docs say these extensions “run in an isolated sandbox” inside a Web Worker with no access to the window or the DOM.
That has two consequences. The code cannot touch your product pages, and it loads only after the customer has paid. A survey on the Thank you page cannot cost you a conversion that already happened.
My own scanner agrees. When the App Speed Index detects the KnoCommerce or Fairing script on a storefront, it scores it at about 50ms of blocking time and tags it post-purchase only. For context, I measure Klaviyo’s storefront script at 120ms and Hotjar at 110ms in the same index.
The speed risk comes from the extras. Zigpoll sells exit-intent and product-page surveys, and Grapevine runs on-site surveys too. Those load a script on the pages that sell. Run my app bloat detector on your store before and after you switch one on.
Will my old survey still work after the Order status page change?
Check this before you pick any app. Shopify’s timeline says script tags stop running on the Order status page for non-Plus stores on August 26, 2026, a year after Plus stores lost them. Shopify’s replacement is a customer account UI extension or a web pixel.
If your survey was pasted into the old Additional scripts box, or came from an app that injected a script tag, it has stopped collecting answers. I wrote up the full migration in Shopify additional scripts deprecated.
Fairing, Zigpoll and Grapevine list checkout support on their App Store pages. KnoCommerce’s listing names the order confirmation page but not checkout extensions, so ask its support how it renders before you install. Whichever you run, open the dashboard and confirm responses kept arriving after August 26. A flat line to zero means the old install died.
Which post-purchase survey app should I pick?
Pick by your order volume and the one integration you cannot live without. My rule set:
- Under 200 orders a month: Fairing’s free plan. Unlimited questions, 25+ integrations, $0.
- You want the lowest bill at any volume: Grapevine at $25 flat. It sends data to Shopify Flow, Klaviyo and GA4.
- You live in Triple Whale: Fairing or KnoCommerce. Both list Triple Whale as a native integration.
- Above about 3,000 orders with a set budget: KnoCommerce Analyst. The $119 stays flat while Fairing keeps stepping up.
- You want surveys beyond the Thank you page: Zigpoll, if on-site, email and SMS research is worth $399 to you.
The question you ask matters more than the app. Keep it to one required question, shuffle the answer order, and list the channels you actually buy: Meta, TikTok, Google, podcasts, creators, a friend. Add “Other” with a text box so you catch the channel you forgot.
What do I do with the survey answers?
Compare the survey’s channel share against what each ad platform claims, every month, over at least a few hundred responses. If Meta Ads Manager claims 60% of orders and only 35% of buyers say “Instagram or Facebook,” your platform numbers are inflated and your blended CAC is the honest metric.
Then route the answers somewhere they change decisions. Tag each order with the answer, push it into Klaviyo, and segment email flows by acquisition channel. A podcast buyer and a TikTok buyer rarely respond to the same second email.
This is also where I start most CRO audits. Before I touch a product page, I want to know which traffic converts and which traffic only looks like it does. If the survey says creators drive your best customers, the landing pages for creator traffic get fixed first.
Setting this up is a 2 to 4 hour job in my experience: install, write the question, wire one integration, and verify responses land on real orders. At my published $50 an hour that is $100 to $200.
How do I verify my survey is working in 5 minutes?
- Place a test order on your store and confirm the survey shows on the Thank you page and again on the Order status page.
- Open the app dashboard and confirm your test answer is attached to that order number.
- Open the integration (Klaviyo profile, Triple Whale, or GA4) and confirm the answer arrived there too.
If step 3 fails, your survey collects data nobody will act on.
The takeaway
- Price the survey at your real order volume, not the entry plan on the listing.
- Budget $119 for KnoCommerce, because the $19 plan has no integrations.
- Keep the survey on the Thank you page so it never touches product page speed.
- Confirm responses kept arriving after the August 26, 2026 script tag cutoff.
- Compare survey channel share to platform claims monthly before you move ad budget.
If you want a second pair of eyes on your attribution and conversion data, my engagement terms and rates are public, and the Elevar vs Littledata vs Analyzify comparison covers the server-side tracking half of the same question.
Kaspian Fuad is a Shopify developer and CRO specialist with 12 years and 100+ stores behind him. He publishes his rates and engagement terms on kaspianfuad.com.