Revenue Engineering / 2026/4/10

Affiliate Infrastructure Overhaul: PA-API Independence, 3-Button Cards, and the FANZA Sidebar Experiment

The Day Amazon Kicked Us Out

On April 10, 2026, we attempted to migrate netouyonews affiliate blocks from hand-coded HTML to Cocoon’s native [amazon asin="X"] shortcode. It looked clean — one line per book instead of fifteen.

Then we hit AssociateNotEligible:

Your account does not currently meet the eligibility requirements
to access the Product Advertising API.

Amazon’s PA-API requires 3+ completed sales in 180 days to maintain access. Our 75 clicks hadn’t converted enough. The shortcodes rendered as broken error cards visible only to admins, but public-facing product displays were reduced to bare text links.

Time to fix: 0. We had to build something that doesn’t depend on Amazon’s mood.

The 3-Button Card Architecture

We designed a hand-coded HTML card that works with zero API dependencies:

┌─────────────────────────────────────┐
│ [Book Cover Image]  Title           │
│                     Author          │
│  [Amazon] [Rakuten] [DMM]           │
└─────────────────────────────────────┘

Image Sources (No API Required)

Store	Image Source	Auth Needed
Amazon	`m.media-amazon.com/images/P/{ASIN}.jpg`	None
Rakuten	`thumbnail.image.rakuten.co.jp/...?_ex=400x400`	App ID (search only)
DMM	`pics.dmm.com/mono/hobby/{cid}/{cid}pl.jpg`	None

The Amazon image CDN trick (m.media-amazon.com/images/P/{ASIN}.jpg) returns book covers for any valid ASIN without authentication. This is the foundation of our PA-API-free system.

Affiliate Link Formats

Store	URL Pattern	Tracking
Amazon	`amazon.co.jp/dp/{ASIN}/?tag=netouyo01-22`	✅ Associate tag
Rakuten	`hb.afl.rakuten.co.jp/hgc/{AFF_ID}/?pc={target}`	✅ Affiliate ID
DMM	`al.dmm.com/?lurl={target}&af_id=netouyo-990`	✅ Affiliate ID

Book Curation via Rakuten Books API

Instead of trusting manually-entered ASINs (which turned out to be wrong in 2 of 6 posts — 4101104409 was “不毛地帯” not “石油の世紀”), we now curate books using Rakuten’s BooksTotal Search API:

url = f'https://app.rakuten.co.jp/services/api/BooksTotal/Search/20170404'
     f'?format=json&keyword={topic}&applicationId={APP_ID}&hits=3&sort=sales'

This gives us verified (title, author, ISBN, cover image) tuples. No more ASIN guessing.

DMM URL Format Discovery

DMM’s search URL format is non-obvious. We tested 5 patterns:

Pattern	Status
`book.dmm.com/search/?keyword=X`	❌ Redirects to homepage
`book.dmm.com/list/?search_keyword=X`	❌ Redirects to homepage
`www.dmm.com/search/-/list/?searchstr=X`	❌ 404
`www.dmm.com/search/=/searchstr=X/`	✅ 200 OK
`book.dmm.com/search/index/?k=X`	❌ Redirects

The correct format uses =/ not -/list/?. This is DMM’s proprietary URL schema that’s not documented anywhere obvious.

Batch REST API Operations

All 6 existing netouyonews articles were updated via WordPress REST API in a single batch operation:

Fetch each post’s raw content (?context=edit)
Extract old affiliate blocks (regex-based boundary detection)
Rebuild with new 3-button card HTML
POST updated content back

The entire batch (6 posts) completed in ~8 seconds with 0.3s inter-request delay.

Brand Normalization (Bonus)

While we had all posts open, we also ran a brand replacement pass:

NT Media → NT編集部 (across all published posts)
Applied via REST API str.replace() in a single pass

For revenue experimentation, we deployed a sticky sidebar widget with two stacked 300×300 product cards:

Top: DMM.com hobby/figure (美少女フィギュア, mono/hobby API)
Bottom: FANZA videoa ranking #1 (digital/videoa API)

DMM API Image Gotcha

DMM’s mono/hobby endpoint returns imageURL with only list and small keys — no large. But the URL pattern {cid}ps.jpg → {cid}pl.jpg works for 600px images. The API docs don’t mention this.

Deployment

Widget HTML was hand-pasted into Cocoon’s “サイドバースクロール追従” widget area (Custom HTML widget). No REST API for widget management — Cocoon’s widget areas aren’t easily addressable via WP REST.

Cocoon Shortcode: Why We Couldn’t Use It

Cocoon’s [amazon asin="X"] shortcode is elegant — one line, auto-fetches product data, renders beautiful cards with Amazon + Rakuten + DMM buttons.

But it requires PA-API access. Without it:

Cards render as product-item-error divs
Admin sees “AssociateNotEligible” error
Public sees bare “Amazonで詳細を見る” text links

Lesson: Don’t depend on third-party API availability for revenue-critical UI. Hand-coded HTML with CDN images is uglier but indestructible.

Results

Metric	Before	After
Working affiliate links	2/8 posts	8/8 posts
Stores per book	1 (Amazon only)	3 (Amazon + Rakuten + DMM)
Book cover images	0	3 per article
PA-API dependency	Yes	No
FANZA sidebar	None	Sticky widget (2 products)
Brand consistency	Mixed	NT編集部 unified

What’s Next

PA-API recovery: Once Amazon sales hit the 3-sale threshold, PA-API re-enables automatically. At that point, we can optionally switch back to Cocoon shortcodes — but the hand-coded system works fine as a permanent fallback.
Rakuten Affiliate tracking: Currently using hb.afl.rakuten.co.jp wrapper. Need to verify click attribution is working in Rakuten’s dashboard.
FANZA sidebar rotation: Currently static (manual product selection). Phase 2 would auto-rotate weekly via cron + DMM API.
--humanize lint mode: Adding AI-ism detection to validate_mdx.py (e.g., 冷徹, 浮き彫りにする, 紐解く).