HubSpot vs Customer.io vs Klaviyo: Picking a Marketing Automation Stack

Three tools, three different shapes of business

The marketing automation category is deceptively broad. HubSpot, Customer.io, and Klaviyo all send emails, branch on user behaviour, and integrate with websites. At a glance they compete. In reality each was designed around a different centre of gravity, and choosing the wrong one costs six to twelve months of wasted configuration.

Here is our working take after shipping integrations against all three for client sites across Australia.

HubSpot: the all-in-one CRM

HubSpot started as inbound marketing software and grew into a full suite: Marketing Hub, Sales Hub, Service Hub, CMS Hub, and Operations Hub. The marketing module is good, but the product is a CRM with marketing tools attached.

What it does well

Contact management is the star. Every email, meeting, deal, and support ticket lives on a single timeline. Forms on your website create or update records automatically. Sales reps see what marketing has been sending and vice versa. Reporting crosses the funnel end-to-end. For a business where sales and marketing need to operate against the same customer record, HubSpot is hard to beat.

Where it hurts

Cost scales aggressively. Marketing Hub Professional starts around AUD $1,080 per month and jumps fast as contact counts grow. Operations Hub is a separate charge for anything beyond basic automation. The workflow builder is visual and friendly, but struggles with real-time event-driven lifecycle campaigns. It is tuned for scheduled nurture, not "user did X, send Y within two minutes".

Best for

B2B services, B2B SaaS with a human sales motion, agencies, consultancies, and any business where deals are longer than a week and a salesperson is involved.

Customer.io: event-driven lifecycle, engineer-friendly

Customer.io is built around events and user attributes. Your product or website sends events via an API or JavaScript snippet (track("Signed Up"), track("Viewed Pricing Page")), and campaigns trigger off those events with full filter logic.

What it does well

Sophisticated lifecycle messaging. Onboarding sequences that adapt based on what the user actually did. Churn prediction workflows that key off inactivity. Product-led growth motions where email, in-app messages, SMS, and push notifications run from a unified campaign canvas. The Journeys module, the Broadcasts module, and the Parcel email editor combine into something genuinely useful.

Pricing is per-user (rather than per-contact), and the plan allows unlimited emails. For businesses with millions of users but moderate email volume, this is dramatically cheaper than HubSpot or Klaviyo.

Where it hurts

There is no CRM. If your sales team needs deal tracking, pipelines, or contact management, you are bolting on Salesforce or HubSpot CRM alongside. The product assumes engineering capacity. Marketers cannot self-serve new events. They have to ask dev to instrument them.

Best for

B2B SaaS with product-led growth, fintech, consumer apps, marketplaces, and any business where the product itself generates the useful events and where a developer is available to wire them up. This is the shape Atlassian and Canva grew into, and it suits Australian SaaS teams selling abroad.

Klaviyo: the ecommerce lifecycle king

Klaviyo was built for Shopify, and the DNA shows. The product integrates natively with Shopify, BigCommerce, and WooCommerce, pulling order history, product catalogues, and browse behaviour into rich customer profiles.

What it does well

Ecommerce automation out of the box. Abandoned cart, browse abandonment, post-purchase, win-back, replenishment, review request. All pre-built templates with revenue attribution baked in. The reporting tells you exactly how many dollars each flow or campaign generated, down to the discount code and SKU. Predictive analytics (next expected order date, customer lifetime value, churn risk) are built in for any store with enough order history.

Product blocks inside emails pull live pricing, images, and stock from Shopify. If a product sells out, the email automatically swaps in a substitute. That is the kind of integration depth competitors chase.

Where it hurts

Klaviyo is laser-focused on ecommerce. Using it for B2B or services feels like forcing a square peg. Pricing is contact-based and scales steeply past 50,000 contacts. SMS is a separate subscription. Segmentation logic is excellent but the UI can be sluggish on large lists.

Best for

DTC ecommerce on Shopify, beauty and apparel brands, food and beverage, anyone selling physical products direct to consumer.

A decision framework

Cut through the marketing noise with three questions.

1. What generates your best customer signals?

If your product emits events (signed up, invited teammate, hit usage limit, cancelled), Customer.io maps one-to-one. If your signals come from a sales rep entering data (deal stage, meeting booked), HubSpot is the fit. If your signals come from a Shopify store (ordered, abandoned cart, left review), Klaviyo wins.

2. Who owns the tool day to day?

HubSpot is marketer-owned and rep-owned. Klaviyo is marketer-owned with some developer help. Customer.io is engineer-and-marketer co-owned. Without both, it stagnates.

3. What is the lifetime contract value?

A B2B SaaS selling AUD $50k enterprise deals justifies HubSpot's price and the sales team infrastructure around it. A DTC brand selling $80 skincare does not. Every dollar of MRR on automation needs to pay for itself in attributable email revenue, and Klaviyo's reporting proves that. A usage-based app with $10 ARPU needs Customer.io's unlimited-sends model to be economic at all.

Migration pitfalls

Migrating between these tools is harder than the vendors admit.

Data model mismatch

HubSpot has Contacts, Companies, Deals, Tickets. Customer.io has Users, Objects, Events. Klaviyo has Profiles, Events, Metrics. Mapping between them loses fidelity. A HubSpot "Deal" does not cleanly become anything in Customer.io without custom objects.

Consent and deliverability

Moving a suppression list is non-negotiable. Take the unsubscribes with you, or you will spam people who opted out and damage your sender reputation. Warm the new sending domain over two to four weeks before full cutover.

Historical campaigns

Nobody migrates historical sends. Accept that your new tool starts empty and your old tool holds the archive for compliance.

Event taxonomy drift

Event names on the old tool (Purchase Completed) rarely match your new tool's conventions (Order Completed). Lock in a new naming scheme before migration so you do not carry inconsistency forward.

Getting started

At CodeDrips, we integrate all three platforms into client websites and help pick the right one up front, before a wrong choice costs a year. If you are weighing options or mid-migration, let's talk through your stack.