What percentage of revenue should come from email?

For a healthy eCommerce brand, email and SMS should carry a meaningful share of total revenue. If that share is thin, your email channel is underperforming and there's revenue to recover. If email is doing almost all the work, your acquisition channels may need more investment.

How much should I spend on paid ads to start?

You need enough monthly spend to get meaningful data. Anything less and you're not generating enough clicks for the algorithms to optimize. Google Shopping and Meta retargeting can work at lower budgets. Prospecting on Meta needs more room to learn.

Can email completely replace paid ads?

No. Email can't acquire new customers. It can only nurture and convert people who already joined the list. Without an acquisition channel such as paid ads, SEO, referrals, or organic social, your email list stagnates and revenue plateaus. You need both.

What about SMS marketing?

SMS fits alongside email as a retention and conversion channel. It has higher open rates but higher costs per send. Use SMS for time-sensitive messages: flash sales, back-in-stock alerts, and cart abandonment. Don't spam people's phones with newsletters.

How do I measure the return of each channel?

Use Klaviyo's built-in attribution for email. Use Google Analytics 4 with proper UTM tagging for paid ads. For the full picture, look at blended metrics: total revenue divided by total marketing spend. Channel-level return is useful but can be misleading due to attribution overlap.

Channel Strategy

Email keeps paying after you send. Paid ads stop the moment you pause. 150+ clients still need both.

This comparison gets framed as a fight. It isn't. Email only works if you have a list. And the most reliable way to build that list? Paid ads. These two channels aren't competitors. They're partners. Paid ads acquire the customer. Email turns them into a repeat buyer. The brands that win understand that loop. They don't argue about which channel is better. Here is the breakdown from an agency that runs both every single day.

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150+

Clients

$70M+

Revenue

$23M+

Ad Spend

Klaviyo Gold Partner

Partner

The email vs paid ads debate misses the point entirely. They solve different problems at different stages. Paid ads put your brand in front of new people. Email nurtures those people into loyal, repeat customers.

The real question isn't which one to pick. It's how much to invest in each based on where your business is right now. A brand with no list should invest in paid ads for acquisition. A brand with a large list and neglected flows should put more into email. Let's walk through the honest tradeoffs.

Email Marketing vs Paid Ads: feature by feature

Feature	Email Marketing	Paid Ads
Return	For a well-run eCommerce email program, return is high because the cost is almost entirely labor. The sends themselves are cheap.	Paid return is lower than email on a well-built list. Strong accounts do better. But you're paying for every click and impression. Revenue stops when spend stops.
Customer Acquisition	Email doesn't acquire new customers. It nurtures and converts existing contacts. You need another channel, paid, SEO, or organic social, to build the list first.	The primary acquisition channel for most eCommerce brands. Google and Meta ads put your products in front of people who've never heard of you.
Customer Retention	The single best retention channel. Post-purchase flows, win-back sequences, VIP segments, and replenishment reminders turn one-time buyers into loyal customers.	Poor retention tool. Retargeting existing customers is expensive and inefficient compared to email. You're paying to reach people who already gave you their email.
Cost Structure	Low variable cost. Klaviyo charges per contact, not per send. Once someone is on your list, sending them emails costs almost nothing. The investment is in strategy and content.	High variable cost. You pay per click on Google or per impression on Meta. Costs increase as you scale and competition intensifies. There's no free traffic on paid.
Time to Results	Quick wins are available if you have an existing list. Fix your abandoned cart flow and you'll see the gap fast. Building a new program from scratch takes longer.	Immediate traffic and sales from day one. Turn on ads, get clicks. The learning period takes time for algorithm optimization, but you see data on day one.
Compounding Effect	Strongly compounding. Every new subscriber increases your email channel's value. A list you own is an asset that generates revenue without additional media spend.	Non-compounding. Ad spend today doesn't make tomorrow's ads cheaper. You're renting attention, not building an asset. When the budget stops, so does the traffic.
Platform Dependency	You own your list. If Klaviyo raises prices, you export your contacts and move. No algorithm changes can take your audience away.	Fully dependent on Google and Meta. Algorithm changes, policy updates, and ad cost inflation can crater your performance overnight. You own nothing.

Our recommendation

Stop thinking about this as either/or. The winning formula for eCommerce is paid ads for acquisition, email for retention and maximizing LTV. Healthy brands split credit across email, paid, SEO, and organic rather than betting the number on one channel.

If you're forced to choose one starting point: pick paid ads if you have no list and need customers now. Pick email if you already have a list and you're not sending anything, or just blasting the whole list with the same campaign every week. Get both channels running. They're much more powerful together.

Pick Email Marketing if...

Put more into email marketing if you already have a list, if email currently drives a thin slice of total revenue, or if your flows haven't been touched in a long time. The fastest revenue lift most eCommerce brands can get is fixing their abandoned cart, welcome, and post-purchase flows. It's not glamorous, but it's money sitting on the table.

Pick Paid Ads if...

Invest in paid ads if you're a new brand with no audience, if you have a product that sells well visually, or if you need revenue now, not next season. Paid ads are the fastest path to customers and cash flow. Just make sure you're capturing emails from day one. Otherwise you're paying to acquire customers you can't afford to acquire again.

FAQ

Honest answers to
common questions

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