CommerceHub is one of the oldest multi-channel platforms out there. Their feed capabilities come from an acquisition of Mercent.
Some of the disadvantages of CommerceHub are their long-term contracts and fees which tend to be a percentage of revenue/sales on different channels.
You can see a comparison of the best CommerceHub alternative and competitor Feedonomics, which shows some of the key differences, including how Feedonomics doesn’t have long term contracts with flat monthly pricing.