How do you plan an ecommerce marketing budget?
Plan an ecommerce marketing budget backwards from your revenue target: set target revenue, your contribution margin and the MER you can stay profitable at, then work out total ad spend from those three. Split that spend across channels that capture demand, create demand and bring customers back, and rebalance the split every month using real data.
Most brands do it the other way round. They start with "this much for Meta, this much for Google" and look at revenue afterwards. That makes it almost impossible to see which channel actually earns a profit. We covered single-channel budgeting in our Meta budget guide; this post is about the total plan across channels.
How do you calculate your total marketing budget?
The math rests on three numbers: target revenue, contribution margin and target MER. Contribution margin is what's left after product cost, shipping, payment fees and returns. Target MER is the ratio you want between total revenue and total ad spend, and it has to rise as your margin falls.
Example: you aim for 2,000,000 TL in monthly revenue and your contribution margin is about 40 percent. If you want 15 percent of revenue left as contribution profit after ads, you can spend 25 percent of revenue on advertising. That's an MER of 4 and a monthly ad budget of 500,000 TL. Run the same math for a brand with a 25 percent margin and the picture changes completely: ad share drops to 10 percent and MER needs to be 10.
These figures are an example; plug in your own margin and profit target. Our guide to ecommerce profit margin shows how to get the margin right.
How should you split budget across channels?
Grouping channels by the job they do, rather than by name, leads to better decisions:
| Channel group | Example channels | What it does | How to measure it |
|---|---|---|---|
| Demand capture | Google Search, Shopping, brand keywords | Turns people already searching into buyers | ROAS, CPA, impression share |
| Demand creation | Meta, TikTok, YouTube, Demand Gen | Introduces the product to people not yet searching | MER, new customers, CAC |
| Re-engagement | Retargeting, email, SMS, WhatsApp | Brings visitors and customers back to buy again | Repeat purchase rate, customer lifetime value |
| Organic and long term | SEO, content, creator partnerships | Builds up over time and reduces ad dependence | Organic revenue, branded searches |
The right split depends on where your brand is. A new brand has little search demand; however high its Google Search budget, it can't spend it, so growth has to come from demand creation. An established brand gets more out of demand capture, but that alone won't carry growth. Research Google ran with Analytic Partners, published on Think with Google, suggests multichannel retailers put around 60 percent of budget into digital and 40 percent into traditional channels, while noting it isn't a guaranteed formula for every retailer. Treat ratios like this as a starting point, not a rule.
How does the split differ for new and established brands?
For a new brand, most of the budget goes to demand creation, because nobody is searching for you yet. Creative testing on Meta and TikTok is the main job in this phase. On Google you try to capture product searches with Shopping and Performance Max, but volume is limited.
For an established brand the picture shifts. Branded searches and repeat purchases have grown, so channels like Google Search and email take a bigger share of revenue. The common mistake here is cutting demand creation because "its ROAS is low". A few months later branded searches fall too, and the cause is spotted late. When you cut a demand creation channel, watch branded Google searches and direct traffic as well; if both drop together, the channel you cut was doing more than it looked.
How do you build the budget plan step by step?
This order keeps the plan consistent:
- Set target revenue. Monthly and seasonal; write peaks such as 11.11, Black Friday and the holiday season separately.
- Calculate contribution margin. By product group if you can.
- Set target MER. Derive it from margin and profit target.
- Work out total ad budget. Target revenue divided by target MER.
- Split by channel group. Decide the share for demand capture, demand creation and re-engagement based on your brand's stage.
- Reserve a test budget. Keep a small part of the total for new channels, creatives or campaign types.
- Track weekly, reallocate monthly. Move budget from channels with falling marginal return to rising ones.
How should you adjust budget for peak season?
In Turkey, November is the busiest month of the year because of 11.11 and Black Friday. Click and impression costs rise, but so do conversion rates. Raising budget gradually two to three weeks before the peak gives the algorithms time to learn.
One technical detail on Google Ads is worth knowing. According to Google's help page, a campaign can spend up to twice its average daily budget on busy days, but over a month total spend won't exceed about 30.4 times the average daily budget. Factor that flexibility in when you build a monthly plan from daily budgets. Platforms such as TikTok also set minimum daily budgets at campaign and ad group level, so spreading small amounts across too many channels can leave you below those floors.
How often should you update the split?
Track weekly, decide monthly. Shifting budget on daily swings disrupts how the algorithms learn. In the monthly review, ask one question: where did the last 10,000 TL added bring the most extra revenue and new customers? Marginal return, not average ROAS, should decide. If you want a clearer view of each channel's contribution, incrementality testing is a good next step.
If you'd like to plan budget across channels around your profit target, see our growth strategy service, or request a free growth audit from Performetic to review your current split.
Key takeaways
- Work your marketing budget backwards from revenue target, contribution margin and target MER.
- Group channels by job: demand capture, demand creation, re-engagement and organic.
- New brands lean on demand creation; established brands need a balanced split.
- Ramp budget gradually before peak season and account for each platform's budget rules.
- Track weekly, decide monthly, and judge channels on marginal return rather than average ROAS.