Module 07 · Lesson 3 of 4
Source Share and Competitor Benchmarks
"We appeared in 30 percent of answers" is a sentence that hides three different metrics. Getting them straight is what makes your numbers comparable across months and against competitors, and comparability is the entire point of measuring.
Three shares, defined exactly
| Metric | Numerator | Denominator | Question it answers |
|---|---|---|---|
| Mention share | Queries where you were named or cited | Queries that produced any AI answer | How present are we? |
| Citation share | Queries where you were a displayed source | Queries that produced any AI answer | How often are we the evidence? |
| Source share | Citations of your domain | All citations logged, all domains | Of everything cited, how much is us? |
The denominator rule from lesson 3.4 holds for all three: only queries that produced an AI answer count. Source share is the ecosystem view: it counts your domain against publishers, communities and every competitor at once, which makes it the fastest way to see who actually owns your niche's answers. A domain with 6 percent source share in a niche where the leader holds 40 is not competing; it is attending.
Thresholds turn trends into decisions
With shares tracked monthly, set decision thresholds in advance so movement triggers action instead of debate:
- Citation share up or down five points or more for two consecutive months: investigate (lesson 3.3 interrogation on the flipped queries) before celebrating or panicking.
- Competitor gains five points in one month: one targeted investigation pass, this week. Find the asset; decide whether the slot is ownable.
- Your share flat for a quarter while work shipped: the work is not the work the surface rewards. Re-run the opportunity ranking; something in the queue is mis-ranked.
Write the thresholds down. The value of a threshold is that it fires the same way whether the news is good or bad, and it protects you from re-litigating what "significant" means every month.
| Brand | Mention | Citation | Source share | Move (90 days) |
|---|---|---|---|---|
| TradePublisher-A | 71% | 66% | 38% | +2 |
| Competitor-B | 44% | 38% | 21% | +6 |
| You | 19% | 12% | 7% | +3 |
Reading: you are growing from a small base while a publisher owns the ecosystem; Competitor-B's +6 in 90 days crosses the investigation threshold. The likely explanation is their comparison page shipped in month two (you logged it in Module 6). The decision is already shaped: contest that slot, or concede it and take the two slots the publisher ignores.
- Compute all three shares for yourself from your latest monthly roll-up. State the denominator out loud.
- Add the same three columns for your two named competitors on the identical set.
- Write your three thresholds into the roll-up sheet, with the action each one triggers.
- Mark any threshold you already crossed and schedule its investigation.
What is the difference between citation share and source share?
Why must benchmarks use your identical query set?
Your share is flat for a quarter despite shipping work. What does that mean?
Sources used in this lesson
Google Search Central: AI features and your website