Serving C64 and ZX Spectrum owners, Phil's Retro Spares Shop sells chips, diodes, capacitors and more for competitive prices and with low shipping rates that the larger stores find difficult to match. Due to the nature of the retro computing scene, only low levels of stock are required at any time.
Retro Spares Website
This eCommerce site features nested categories with no practical limit on number, level or contents. Additionally, products can be listed in as many categories as necessary - again with no realistic limit. Since there's very little you can say about (for example) a 5v1 Zener Diode we stopped short of giving each product its own page and instead used the full description in the search results and category listings.
The site uses PayPal's IPN callback which allows customers to buy quickly and easily since the PayPal account details are passed back to the store - not having to enter payment and shipping details is a big time saver.