How do I assess an SEO company's communication style?

By testing it on purpose before you sign rather than forming an impression from friendly calls. Decide first how you want to be kept informed, then give each company the same small tasks: answer a written question about your own site, describe how it would tell you about a bad month, and put you in touch with the person who will actually write to you. How each one handles those tasks is a sample of its communication style; how pleasant the calls were is not.

Start with what you need

Good communication is partly a matter of fit. An owner with ten minutes a month needs a short summary with one decision to make; a marketing manager who reports upward needs detail, figures, and the reasoning behind each change. Write down how often you want to hear from the company, through which channel, and how much detail you can use. That gives you something to judge each company against, instead of rewarding whoever talks most smoothly.

Ask one question in writing about your own site

Send every company on your shortlist the same written question, such as: “Which page on our site would you work on first, and why?” Compare the answers on four points:

1. Does it name a specific page, or stay general?
2. Does it give a reason you can follow without looking up terms?
3. Does it say what effect it expects, and how you would see it?
4. Does it say what it does not yet know?

If an answer uses a term you do not recognize, ask what it means. A company that can explain its work in plain words when asked is showing you how its reports will read. An answer that leaves you more confused than before is a preview too.

Ask how it would deliver bad news

Ask each company to describe, or better, write, the message it would send in a hypothetical case: for example, imagine your organic traffic fell by a fifth last month. A useful message separates what happened from what the company suspects caused it, says what it will check next, and says when you will hear from it again. Watch for messages that blame something outside the company before anything has been checked, that bury the change in good news, or that promise a quick recovery before the cause is known.

Meet the person who will write to you

The person on the sales call may not be the one you hear from each month. Ask for the account lead to join the second conversation, and ask them to describe your site and your goals back to you in their own words. If they cannot do that yet, ask what they would need to learn first. You are checking whether the person who will handle your account listens, and whether their way of explaining things suits you.

Notice what arrives without being asked

The sales period shows you habits. Did the company send a written summary after the call, with the points agreed and the next steps? Did it send what it promised, when it promised it? A company that follows up on its own before you are a client is showing the habit you want once you are paying.

Agree on a written record

Before signing, ask where decisions and changes to your site will be recorded, and who can see that record. A shared log of what was changed, when, and why lets you check any report against the work itself, and keeps the history of your site with you if the account lead changes.

Put the answers side by side. The company whose written answer you understood best, whose bad-news message you would trust, and whose account lead described your business accurately is the one whose communication style fits.