Buy contact lists or subscribe to data?

List buying is one of the few markets where the product begins to degrade before it is even delivered. Between the moment a contacts file is created and the moment your team uses it, people have changed positions, companies have merged, email addresses have ceased to exist. You are not buying a database: you are buying a photograph of a database, taken on a date that the seller prefers not to specify too much. The real question is therefore not “which list to buy”, but “should we still buy lists”.

A list loses value from day one

Let's take the order of magnitude commonly accepted in B2B: 25 to 30% annual depreciation of contact data, or approximately 2 to 2.5% per month. A list of 10,000 contacts purchased today actually already has a few hundred obsolete ones upon delivery. Six months later, around 1,500 records are dead. At twelve months, a quarter. At 24 months, almost half of your investment no longer corresponds to anything real.

And the degradation is not uniform: it hits the most dynamic profiles first — precisely those that interest you. A contact changing positions is often a signal of opportunity; in a fixed list, it's just a line that silently becomes false.

Calculation over 24 months

Let us pose an illustrative scenario. A team buys a list of 10,000 contacts at €0.30 per unit, or €3,000. To maintain a usable volume, it buys a list equivalent to 12 months, then 24 months: €9,000 in total. Between two purchases, the base continually deteriorates; on average over the period, around 15% of active listings are false at any time. Add the invisible cost: campaigns sent to dead addresses which hamper deliverability, hours of sales staff spent verifying manually, decisions made on conversion rates calculated on a fictitious denominator.

Faced with this, a subscription to a maintained flow – say a plan of €300 to €400 per month over the same scope, or €7,200 to €9,600 over 24 months – costs a comparable amount. But the counterpart is not the same: instead of three successive photographs of an already past reality, you have at all times a basis which converges towards the real state of the market. The cost is similar; the delivered value has nothing to do with it.

What the subscription changes in uses

The difference goes beyond economics. When data is a stock, each exploitation exhausts it: we hesitate to segment finely, we keep questionable files "just in case", we plan campaigns based on the supposed freshness of the file. When the data is a flow, these reflexes disappear:

• Triggers become possible : a change of position or a new published offer can trigger an action the same day, not the next list purchase.

• Confidence returns : teams stop maintaining their parallel files when the central tool is permanently reliable.

• Reporting becomes honest again : the rates are calculated on existing contacts.

The plan rather than the credit

One economic model point deserves to be underlined. Many suppliers bill on credit: each enrichment, each verification consumes a paid unit. This model creates a perverse incentive — you ration the freshness of your own data to control the bill. A fixed price flow aligns interests: the supplier has an interest in the index being fair, it is in your interest to refresh without counting.

Where does the flow come from

A data subscription is only credible if the upstream index is actually maintained. This is the core business of sourcing.sh: an index of around 200,000 companies, 123,000 profiles, 98,000 schools and 1.4 million job offers, continuously populated by agents and partner sources, and delivered to where you work — CRM, ATS, API or AI agent via MCP. Our thesis is that SaaS applications will gradually fade behind the databases that feed them; you might as well subscribe directly to the base.

The ad hoc list had its day, that of quarterly campaigns and Excel files. If your trading actions now trigger on signals, your data must arrive at the same rate as the signals.