I've sold on Delcampe and actually I suspended my sales there due to lack of activity.
Cons:
If you want to be noticed on Delcampe you have to be constantly adding new material otherwise your listings just get buried. It doesn't help that some sellers will end their old listings and relist them as new just to get back on top of the listing feeds.
Also, Delcampe installed a fee for every item that is sold. It ranges from 12 cents to 18 cents depending on your subscription status. It acts like a retroactive listing fee. Intentional or not, it prevents the sales of lower priced items. It's actually cheaper to sell low priced items on
ebay if you list on
ebay without a listing fee.
There is less activity and potential buyers on Delcampe thus the auction format is probably not the best way to sell. Most people who are successful on Delcampe use fixed price listings.
The bulk listing program is absolutely horrible. The page to list items one by one is a better format and easier to use.
Pros:
Sellers can select a variety of payment methods.
Final value fees are less and they do not take a percentage of shipping costs unlike
ebay.
The categories for most countries are better defined (although you can list an item only in one category).
Easy to send invoices, leave feedback and mark items as shipped.
Feedback is more open and one can edit it.
You can write longer title descriptions than
ebay.
It's a true international site - no .ca, .uk, etc.
There's a lot going for the site however I found out that I just don't get the same volume of sales as I do with
ebay. If Delcampe ever removed that fee per item sold I'll probably reopen my store there.