What is grounding?
Grounding is when Cowork reads your own material - files, emails, meetings, spreadsheets, and where connected, the web - before it does the job you've asked for. It's what turns a generic answer into one about your business. It's also the main driver of cost: every source Cowork retrieves spends credits, so a well-grounded task costs more than an ungrounded one and is almost always worth it.
The practical rule is that gathering costs more than making. A proposal written from a blank brief is cheap and generic. The same proposal grounded in the client's email thread, your last three proposals and your pricing sheet costs two or three times the credits and arrives close to sendable. Paying for the grounded version is nearly always the right call.
Where grounding gets expensive without getting better is scope. Ask Cowork to 'look at everything' and it will - and you'll pay for the retrieval of material that didn't matter. Naming the sources you want is the cheapest optimisation there is: 'use the Q2 board pack and the sales tracker' beats 'use our files'.
Grounding also sets the boundary of what Cowork can do. It can only ground in what it can reach - Microsoft 365 by default, other systems via connectors. If the material lives in your practice management, ERP or CRM system, Cowork can't ground in it without a connector, and the output will be thinner than you hoped.
More relevant, certainly - it's built from your material with citations you can follow. Reliability still depends on checking: grounded answers read confidently even when a source was out of date.
You can narrow it - name the sources, skip the web. Turning it off altogether usually saves pennies and costs quality. The better economy is a tighter brief.
The definitions are the easy part. Whether Cowork is the right spend is a different question.
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