certainly would, not so much as a sale source, but as a marketing resource. In fact not just eBay, I would consider using any free listing platform to use like that. Listing things at cost to get some page views, of course factoring in my shipping and sales fees into the mix as well. You don't want to be loosing money listing, but right now with your own sites, it's important to start getting traffic.
Sites like eBay can be an excellent source of customer contact, create special offers, two for one or bundled offers for those who subscribe to your news letter. Once you have the subscriptions, you can then direct them to your site where you have far more stock listed and of course you have better margins.
That's one way to build up traffic effectively, however if you are getting the clicks, but no sales, may well be worth while taking a closer look at how you stack up in the market place. Just because you are getting traffic to your site doesn't mean an automatic sale, in fact if you aren't competitive on price, don't have a good feel to your site, come off as a new seller and countless other things, customers will leave your site as soon as they get there.
Definitely look at opening your marketing channels up wider, but take a good look at your site/s, make sure everything there is as finely tuned to converting a customer into a sale as possible or any marketing efforts in getting customers there could well just be a waste of time.