Share of traffic — the metric nobody tracks but should

Your traffic went up 30% last quarter. Congratulations. Your competitors went up 50%. You actually lost ground.

Absolute traffic numbers are comforting and misleading. A rising line feels like progress. But if the category is growing faster than you are, your relative position is weakening — and relative position is what determines whether you win deals or lose them to competitors.

Share of Traffic measures what absolute numbers hide: your website's traffic as a percentage of total category traffic.

The definition

Share of Traffic = Your visits / (Your visits + Competitor visits)

If you got 10,000 visits last month and your three main competitors got 15,000, 20,000, and 5,000 respectively, your Share of Traffic is:

10,000 / (10,000 + 15,000 + 20,000 + 5,000) = 20%

Track it monthly. If that 20% drops to 18% even while your absolute traffic grows, something is wrong.

Where the data comes from

Your own traffic: GA4 or your web analytics tool. Exact numbers.

Competitor traffic: this is the hard part. Options:

1. SimilarWeb

The most reliable source for competitor traffic estimates. Provides monthly visits, traffic sources, geo breakdown, and engagement metrics for any domain. Paid API, but the data is solid for mid-to-large sites.

2. SEMrush / Ahrefs

Both estimate organic traffic based on ranking positions and keyword volumes. Less accurate for total traffic (they miss direct and referral) but good for organic share specifically.

3. GSC impression share (free proxy)

A creative workaround: if you share ranking space with competitors for the same keywords, GSC impression data can approximate relative organic visibility.

-- models/intermediate/int_organic_share_proxy.sql
SELECT
    DATE_TRUNC(search_date, MONTH) AS month,
    SUM(impressions) AS your_impressions,
    SUM(clicks) AS your_clicks,
    SAFE_DIVIDE(SUM(clicks), SUM(impressions)) AS your_ctr
FROM {{ ref('stg_gsc__search_performance') }}
WHERE query NOT LIKE '%warehows%'  -- exclude branded queries
GROUP BY 1

This gives you your non-branded organic visibility over time. It doesn't directly measure competitors, but a declining trend signals you're losing share even if you don't know the exact number.

Building the model

If you have SimilarWeb or SEMrush data flowing into your warehouse:

-- models/marts/mart_share_of_traffic.sql
WITH all_traffic AS (
    SELECT
        month,
        'warehows' AS brand,
        visits
    FROM {{ ref('stg_ga4__monthly_traffic') }}
 
    UNION ALL
 
    SELECT
        month,
        competitor_domain AS brand,
        estimated_visits AS visits
    FROM {{ ref('stg_similarweb__competitor_traffic') }}
),
 
category_total AS (
    SELECT month, SUM(visits) AS total_visits
    FROM all_traffic
    GROUP BY 1
)
 
SELECT
    a.brand,
    a.month,
    a.visits,
    ct.total_visits,
    SAFE_DIVIDE(a.visits, ct.total_visits) AS share_of_traffic,
    LAG(SAFE_DIVIDE(a.visits, ct.total_visits))
        OVER (PARTITION BY a.brand ORDER BY a.month) AS prev_month_share
FROM all_traffic a
JOIN category_total ct ON a.month = ct.month
ORDER BY a.month, share_of_traffic DESC

Why relative position matters

Three scenarios to illustrate:

Scenario A: You're growing, market is flat. Your traffic: +20%. Competitors: +5%. Your share: growing. You're winning.

Scenario B: You're growing, market is growing faster. Your traffic: +20%. Competitors: +40%. Your share: shrinking. You're losing ground despite good-looking absolute numbers.

Scenario C: You're flat, market is shrinking. Your traffic: 0%. Competitors: -15%. Your share: growing. You're winning by not losing.

Scenario B is the dangerous one because it feels like success. The dashboard shows green arrows. The executive summary says "traffic up 20%." Nobody mentions that the category grew 40% and you captured none of the incremental demand.

What to track alongside it

Share of Traffic is most useful as part of a competitive dashboard that also includes:

Together, these paint a picture that no single metric can: are you gaining or losing ground, and why?

The practical version for SMBs

If SimilarWeb is too expensive for your stage, here's a lightweight alternative:

1. Track your own GA4 traffic monthly. Exact numbers from your staging model.
2. Estimate competitor organic traffic via SEMrush free tier. Not perfect, but directionally useful.
3. Monitor GSC non-branded impressions. If your non-branded organic impressions are declining while your content output is steady, competitors are outranking you.
4. Set Google Alerts for competitor brand names. Free, surprisingly useful for catching launches and press.

Build a simple spreadsheet (or better, a dbt seed + model) that tracks these monthly. The precision doesn't need to be perfect — the trend is what matters.

When to worry

Three signals that your Share of Traffic is in trouble:

1. Your organic sessions are flat while you're publishing more content. The content isn't ranking, or competitors are pushing you down.
2. A competitor's domain authority is climbing faster than yours. They're building backlinks or publishing at higher velocity.
3. New competitors appear in your GSC query set. Domains you haven't seen before start taking impressions for your keywords.

None of these show up in your absolute traffic numbers. They only surface when you measure relative position.

The honest constraint

Competitor traffic data is always estimated. SimilarWeb is the best available, but it's not GA4-level precise. SEMrush organic estimates can be 20-50% off for smaller sites. The numbers are directionally useful, not gospel.

This means Share of Traffic is a trend metric, not a precision metric. Don't obsess over the exact percentage. Watch whether your share is growing, stable, or declining over 3-6 month windows. That trend is reliable even when the individual numbers aren't.

Your traffic went up 30%. The question isn't whether that's good. The question is: good compared to what?

We build competitive-intelligence models that track your Share of Traffic, Share of Search, and keyword overlap in one warehouse — so you know whether you're winning or just growing slower than the market. Book a discovery call.