Position is a power law. Rank trackers exist to climb it.
The viral "build a rank tracker with Claude for 50¢/month" pitch works because the underlying loop is simple: query a SERP API, log your position, watch the CTR curve do the rest. Slide your rank — watch traffic collapse or explode.
What a rank tracker actually does
It's a scheduled API call
Trackers query a SERP API (or headless browser) for each keyword daily, parse the results, and find your domain's position. 50 keywords × 30 days = 1,500 checks. At typical API pricing (~$0.30–0.60 per 1,000 SERPs), that's literally under a dollar a month — the "50 cents" claim is real math, not magic.
Why position matters so much
Aggregate CTR studies (Advanced Web Ranking, Backlinko) put #1 at roughly 27–32% of clicks, #2 at ~15%, #3 at ~10%, then a long tail: #5 ≈ 6%, #10 ≈ 2.4%. Moving from #7 to #3 doesn't add a few clicks — it roughly triples traffic. That's the whole business case for SEO.
The 4 pieces to build one
(1) keyword list in SQLite, (2) a cron job hitting a SERP API, (3) a parser that records position, url, date, (4) a chart page. An LLM can scaffold all four in one session — the ongoing cost is only the API calls. No subscription because you own the pipeline.
What cheap trackers miss
Localization (rankings differ by city), personalization, and SERP features: an AI Overview or featured snippet above #1 can cut everyone's CTR by a third. Serious trackers record the whole SERP layout, not just your number — worth adding once the basic loop works.