Your household stays private. Prices become visible.
When many households digitise their receipts, an actual price mirror emerges from anonymised data — without your household becoming visible. This is how price transparency actually helps.
Two truths at once. Your individual receipt stays your individual receipt. Thousands of them at once create a price picture nobody else can deliver.
Why there's no real price transparency today.
Consumers have less insight into real price developments than they should — and that isn't due to a lack of data, but to its nature.
Statistics are too slow
The Federal Statistical Office publishes monthly — often with weeks of delay. When a product gets more expensive today, it only shows up in a statistic six weeks later. By then it's a different world.
Industry data has interests
Trade associations and consumer research institutes deliver numbers — but they work for their paying clients. Whose data do you see when a discounter claims to be the cheapest?
Comparison sites have blind spots
They show advertised online prices, but don't know about promotions, discounts or loyalty cards at the till. Local markets, cash purchases and small shops don't appear at all.
What emerges from many receipts.
Four applications that become realistic from aggregated receipt data — without individual households becoming visible:
Regional price mirror
What does a product actually cost in your region? Not the online price, but the real till-receipt price — from actual purchases on the ground.
Real-time trends
Which products are getting more expensive right now? Which categories are shifting? Aggregated data shows movements almost live, not just after months.
Brands vs own-brands
How big is the real price difference between brand and own-brand? Is the markup actually worth it, or is it just felt that way?
Seasonal patterns
When are strawberries cheapest? When does olive oil structurally rise? Seasonal waves become visible from real purchases.
You don't share a receipt. You become part of a picture.
Bon.line uses a deliberate separation: your household works with your receipts, your people, your analyses. What goes outside — if anything — is an anonymised statistical figure where your individual receipt merges with hundreds of others into a single data point.
Nobody sees "you spent €15 on sweets this week". What becomes visible is a community trend like "chocolate prices in southern England rose by 4 %" — and in the end that helps you and others make better decisions.
"We don't sell shopping profiles. We don't want to make you transparent — we want to make visible where prices are squeezing." — from the Bon.line manifesto
How anonymisation works technically.
Trust must be substantial, not just promised. Three technical layers make sure your household stays anonymous — even when aggregated data is created.
1. Data separation
Account and billing data (your email, payment method) are technically separated from household data (receipts, people, categories). In the aggregated system there is no bridge back to the person.
2. Pseudonymisation
Before every aggregation, identifiers are replaced by pseudonyms. Your household becomes a random hash that allows no conclusion about the account — not even internally at Bon.line.
3. K-anonymity
A data point is only published if it is composed of at least k households. For rare products or small regions, the granularity is reduced — never the other way round.
Privacy by design isn't a checkbox, it's an architecture. Whoever upholds these separations technically can't lose or resell data by accident.
Thinking bigger.
"A receipt helps you. Many receipts can show long-term how prices really develop — anonymised, aggregated, with no link back to individual households."The vision behind Bon.line: price transparency through real data, with full protection of your privacy.
When many small truths become a big one.
Your receipt is small. Thousands of receipts at once form a picture nobody else can deliver — and that helps everyone who shops.
Become part of it →Frequently asked questions
Are my individual receipts or shopping profiles sold?
No. Individual receipts, personal baskets or household profiles are never passed on — neither sold nor transferred in any way. Only statistically aggregated and anonymised price data can long-term contribute to a community picture of real price development. This separation is anchored technically in the system, not just in the terms.
How does the anonymisation work concretely?
Three layers interlock: First, account and billing data are processed technically separated from household and receipt data. Second, for every aggregation, pseudonyms are used that allow no link to the account. Third, before any external publication, the principle of k-anonymity is applied — a data point is only released if it is composed of at least k households.
From how many users does price transparency become meaningful?
First regional statements become possible from a few thousand active households. For nationwide category trends, tens of thousands are needed. Bon.line builds this expressiveness step by step — until then you use the personal index for your household, which works from day one.
Can I opt out of my data being used for aggregated statistics?
Yes. In your settings you can decide at any time that your data is used exclusively for your personal index. Bon.line then works for you unchanged — you just aren't part of the aggregated analyses. We respect that decision without follow-up questions, without nudges, without pop-ups.
What is real price transparency concretely useful for?
Four applications are realistic: regional price mirror (what does a product cost in your region?), category trends in near real-time (which products are getting more expensive?), difference between brands and own-brands, and seasonal patterns (when is which product cheapest?). Today's sources are either too slow, too coarse, or come from interest-driven sources.
Why not just trust comparison sites or the Federal Statistical Office?
Comparison sites show advertised prices, not real till-receipt prices with discounts, promotions and loyalty cards. The Federal Statistical Office delivers high-quality but slow average data. Bon.line closes the gap between them: data from real purchases, in near real-time, with product granularity — and fully independent of industry or retail interests.