What's the best site to sell old tech equipment & memorabilia? (eBay, Craigslist, Facebook Marketplace or elsewhere)

I would very much agree with those recommending eBay as your best chance to find the audience you seek. eBay has by far the largest community of buyers who would be interested in the products you've described that you're trying to sell.Also,if you can't find buyers for your old mobile tech and promotional items, you might consider donating them to the Computer History Museum in Mountain View, CA. I used to work there and their artifact collection includes quite a lot of old Silicon Valley marketing items.

Check out http://www.gaang.org/, it provides a much better SEO friendly algorithm which Google loves. Most classifieds only utilize the category in the url of the listing. When you list on http://www.gaang.org/, we offer advanced meta tags and enable the user to publish their listing with title in the url. Better exposure locally as well as globally. Absolutely free listings with the ability to boost your post to the front page for even more visibility.

The way to get the most money is by selling on . Do auction format and start the bid at $0.99. I always get the most amount of views, watchers, and bids when do it this way.  Don't get worried that it won't sell or won't net you the price yours asking. I've ended up getting a price I was way more than happy with about 95% of the time. Also, before listing your item google search for exactly what it is, find the manufactures website and copy & paste the title of the new item into your listing title. This helps for visibility on as well. Lastly, take 8-12 great pictures. I usually take them in the bathroom because it's the most well lit room in the house and is surrounded by white tile.

You would probably get the best for your money listing in an eBay store that specializes in vintage tech. Your items are very specialized and will be sought after by a unique audience. With eBay you get a world wide exposure..

I dislike craigslist because of the scam issues and ebay charges a very high fees.  You can try http://www.123exchanges.com.  It's a new online marketplace to buy and sell second hand goods via videos!