Media & Ad Monetization
Turning real experience and knowledge into trusted articles and social content.
MEDIA × COMMERCE × AI
Take small businesses
to their next step.
ArcThree Media Lab is a venture-development lab that turns real business experience into valuable content, and repetitive work into tools.
OUR BUSINESS
Three businesses
ArcThree brings three pillars together into one media lab.
Cross-border Commerce Support
Lightening the pre-listing workflow for individual sellers with easy-to-use tools.
AI Multi-Agent
A governed AI-collaboration system supporting research, production, and verification.
TOOLS & PRODUCTS
Tools & Products
Working tools you can actually use — released free, one by one.
LIVE · FREE
eBay Shipping & Profit Checker
For US sellers shipping within the US: check package size, estimated shipping cost, and eBay fees to see your real profit margin before you list.
US Domestic edition · for sellers shipping within the US (USD, in/lb). Shipping from Japan? Switch to JP for the Japan → USA edition.
Open tool →
LIVE · FREE
eBay Category ID Finder
Get eBay Taxonomy-recommended category IDs and hierarchy paths from your title or keywords.
For any eBay seller · English and Japanese. Suggestions come from eBay.com's Taxonomy API.
Open tool →
COMING SOON
ArcThree eBay Listing Tool
An all-in-one listing assistant for eBay sellers: title generation, category/specifics, images, duplicate checks, and pre-listing checks (in development).
In preparation