You need to rebuild your site, launch an SEO campaign or start on Google Ads. First reflex: look for an agency. And there you find two distinct worlds: the large national agencies with their polished decks, and the local agencies who talk to you about your town. How do you choose? Here are the real criteria.
What a national agency brings (and what it does not tell you)
A national agency has specialised resources: teams dedicated to SEO, design, development and advertising. Semrush identifies this model as suited to companies needing high production volume and standardised processes. But standardisation often rhymes with rigidity: little flexibility, multiple points of contact, and a follow-up that goes through tickets rather than a phone call.
Ask the national agency how many direct contacts you will have on your project. If the answer is more than two people, expect longer timelines and fragmented communication.
What a local agency brings (and its real limit)
A local agency knows your market, your direct competitors, and sometimes your customers. It can meet you face to face, adjust quickly, and understand the specifics of your catchment area. Moz points out that geographic proximity is a real advantage for local SEO, because the agency intuitively understands the search intent of your audience. Its limit: it may lack expertise in very technical areas such as advanced paid search or large-scale e-commerce projects.
- Responsiveness and availability on the ground
- Understanding of the local economic fabric
- A direct relationship with no intermediary
- Natural coherence for local SEO and Google Business Profile
- Sometimes limited expertise on large advertising volumes
The criteria that really matter for a small company
Agency size is not a criterion of quality. What matters is the alignment between your needs and their specialisation. A small company that wants to dominate its town does not have the same needs as an e-commerce brand aiming at a national market.
Free tool: open Google Search Console and analyse which pages generate the most organic traffic on your site. If those pages target a precise geographic area, an agency specialising in local SEO will almost always be more useful than a generalist national one.
What it concretely changes for your search visibility
If you target customers in a precise geographic area, working with someone who knows that territory speeds up results. Ahrefs shows that local searches represent close to 46% of all Google queries. An agency that does not understand where you are based will miss most of your opportunities. PageSpeed Insights remains a universal tool for checking technical performance, whichever partner you choose.
How to validate your choice before signing
Before any commitment, ask the agency for a quick audit of your existing site. A competent agency uses tools such as Screaming Frog or Google Search Console to bring you concrete data from the first conversation. If their diagnosis reads like a sales pitch with no figures, that is a warning sign.
Always ask to see 2 or 3 client cases similar to yours: same sector, same company size, same geographic area if possible. Past results guarantee nothing, but they reveal the working method.
You can also check an agency's own SEO credibility directly with the Ahrefs Website Authority Checker: an SEO agency that is not visible on Google for its own keywords is a concrete indicator. Whatever your final decision, the objective stays the same: to have a site that genuinely generates customers and not a simple digital shop window.