The verdict
For a small B2B or service team, I'd pick Keap. It is a CRM with payments, and Postscript is built for Shopify stores, not service businesses.
If you sell on Shopify and want SMS to carry real revenue, I'd pick Postscript. Its compliance support and opt-in tools are the reason to choose it over an email tool with SMS added.
The pricing shapes differ. Keap has a single plan priced by contact count and an early termination fee on annual contracts. Postscript bills by message with carrier fees on their own line, so a busy sale week costs more than a quiet one. Model a normal period and a peak period before you commit to either.
Side by side
| 6 points compared | ||
|---|---|---|
| Starts at | $249/mo | $100/mo |
| Free plan | No | Yes |
| API | Yes | Yes |
| MCP server | No | |
| SMS / multi-channel | Yes | Yes |
| Visual automation builder | Yes | Yes |
| Links |
Plans and pricing
Keap
- Keap$299/mo
Postscript
- StarterFree
- Growth$100/mo
- Professional$500/mo
- Postscript AI Plan$699/mo
Who each is for
Choose Keap if…
Pick Postscript when you run a Shopify brand and are serious about SMS as a revenue channel.
The visual flow builder comes with templates for cart and browse abandonment, welcome, upsell and shipping messages. Custom attribution windows let you set how long after a text a sale still counts. Segmentation uses your Shopify data, so you can message by purchase history, location or engagement.
You still send the messages, so know the consent rules for each country you sell to. API access is listed on the Professional tier and above. A store on another platform should check the fit first, and a service business has little to use here.
Choose Postscript if…
Pick Keap when you sell services and want the lead to move from form to booking to invoice without manual chasing.
It tags and nudges leads, books appointments and sends invoices with payment links, all on the contact record. A Business Line gives you a number for calls and texts that stays attached to that contact. Text marketing is an add-on rather than the core.
If SMS is your main channel, or you sell physical products online, it is the wrong shape. It is also not an email design specialist, so check the email features against your needs. Test with a trial before committing to a year.
Other options worth a look
Email, SMS and web push marketing for online stores, with ready-made automations and a free plan to start.
Automates email, SMS and sales follow-up through visual workflows with a built-in CRM and contact lists.