A merchant reports post-preorder payment collection problems, describing billing mistakes and roughly $2,000 in balances they could not recover after the initial deposit.
A STOQ alternative for stores that only need alerts
STOQ (Preorder, Back In Stock) is a well-reviewed, feature-rich app built around preorders, with back in stock alerts as part of a larger bundle. If preorders are not something you need, Kelso is a simpler, alerts-only alternative with a flat send-based price.
Sourcing: competitor pricing and review excerpts below were taken from STOQ's public Shopify App Store listing and review pages in July 2026. At that time STOQ showed a 5.0 star rating across 3,354 reviews and carried the Built for Shopify badge. Pricing changes; check their listing for current numbers.
What you pay, side by side
| STOQ | Kelso | |
|---|---|---|
| Free plan | $0 · 10 preorders/mo, 30 emails/mo, unlimited registrations | 50 sends/mo, unlimited subscribers |
| Entry paid plan | $10/mo (Lite) · 100 preorders, 1,000 email/SMS | $14/mo · 750 sends |
| Mid tier | $29/mo (Pro) · 400 preorders, 2,000 email/SMS | $29/mo · 3,000 sends |
| Top listed tier | $69/mo (Unlimited) · unlimited preorders and alerts | $59/mo · 10,000 sends |
| SMS | Included, billed at $0.025/message | Not offered yet |
| Revenue share or overage fees | None listed | None, ever |
STOQ pricing as listed on the Shopify App Store, July 2026. Kelso pricing is current and listed in full on the pricing page.
What STOQ reviewers report
These are paraphrased from dated, public one-star reviews on STOQ's Shopify App Store review page. They are individual merchant reports, not our claims about every merchant's experience.
A merchant reports the preorder button display became unreliable, appearing inconsistently even after reconfiguring the app.
A merchant reports the app disrupted their custom theme layout and pricing display, and that a "Sold Out" status remained visible after uninstalling, which let customers buy items with zero stock.
A merchant reports an unannounced plan change led to overselling, and that fixing affected orders required contacting customers individually.
What Kelso does differently
- Two-path restock detection. The inventory webhook fires first and a scheduled reconciliation poll runs behind it, so a dropped webhook cannot become a false alert or a missed one.
- A full send audit log. Every alert is accounted for: queued, sent, delivered, clicked.
- A flat, predictable ladder: $14/mo for 750 sends, no SMS per-message billing layered on top.
- A free plan that never paywalls subscriber capture. Only send volume is gated, and that is written down.
- Human support that replies in hours. The promise is published on our support page.
Where STOQ may still fit you
A fair comparison cuts both ways. Based on the same public listing and reviews:
- STOQ holds a 5.0 star rating across 3,354 reviews, and the volume and consistency of that rating is real. Its reviews are dominated by praise for fast, responsive support.
- STOQ carries the Built for Shopify badge and was named to Shopify's Top 25 Built for Shopify apps in 2025. Kelso is new and targets the badge at months 3 to 4.
- STOQ includes SMS notifications, billed at $0.025 per message, plus Klaviyo, Mailchimp, and Omnisend integrations. Kelso is email-first and does not offer SMS yet.
- STOQ bundles preorders, backorders, and deposits alongside back in stock alerts. Kelso does not do preorders. If preorders are core to your store, STOQ may fit better.