Question 1

How is this different from Keepa?

Accepted Answer

Keepa is Amazon-only. PriceWatch JP tracks Amazon, Rakuten, and Yahoo! together, and — uniquely — computes the Rakuten SPU effective price (after points + marathon + shop bonuses). It is purpose-built for the Japanese EC market.

Question 2

How accurate is the Rakuten SPU calculation?

Accepted Answer

We honour every per-programme monthly cap, the shopping-marathon cap, and the global membership cap. With 1 point = 1 yen, plug in your enrolled programmes and we compute the savings down to the yen.

Question 3

Where does the price data come from?

Accepted Answer

Official APIs (Amazon Product Advertising, Rakuten Ichiba, Yahoo!Shopping) plus anonymised browsing data from extension users. We do not scrape.

Question 4

Is my personal data safe?

Accepted Answer

We send only anonymised product-page URLs. We do not collect names, addresses, purchase history, or payment information. The Chrome extension uses minimal permissions.

Question 5

Can I cancel any time?

Accepted Answer

Yes — self-service via the Stripe Customer Portal. We do not pro-rate refunds, but you keep full Premium until the period ends.

Frequently asked questions

How is this different from Keepa?

How accurate is the Rakuten SPU calculation?

Where does the price data come from?

Is my personal data safe?

Can I cancel any time?