When you sell through eBay, you can still deliver digital products online, but you will have to advertise through the classified ads and then have some off-site area where a customer can download an eBook from you.
You cannot put links directly in your classified ad taking them to the download area as this violates the terms of the agreement for classified ads, but you can have an email address to let them email you for details on particular infoproducts that they might be interested in purchasing. That email address can be set up with automatic responders to help guide your customer through your pipeline.
The beauty of classified ads is that you get a sales lead and then you can also step them through your sales pipeline automatically using autoresponders. But, first, let's go over some pros and cons of automatic digital delivery.
The advantages to automating delivery are many. You don't have to fuss with inventory, and you can service your customers any day or night, with almost immediate delivery of their infoproduct. You not only get their email address, an invaluable starting point to building an email marketing list, but you also don't have to pay for stamps or gas to deliver the infoproduct to them. You don't have to provide customer service for people with hardware problems, and the worst that can happen is that you have to refund someone's money because the download didn't work on their particular machine.
Digital delivery is also easy to implement and doesn't require even a college degree to figure out. You can create digital products using word and PDF converters that do all the work for you, basically. You can even find templates for CD covers and use private label products that you customize somewhat to make them your own. It is the easiest way to have a viable product that can be created very quickly and put on the market and sold with practically no start-up costs.
Not everyone has the same exact PC setup and many people operate using outdated software of equipment. What may work great on your PC, should be tested to work on multiple platforms, unless you specify a required platform. You can avoid some of that by using files that work well like .pdf and .mp3 files or even straight HTML files that can be read with any browser. If you get too fancy with your product, like exotic formatting in your ebooks, or strange formats that might or might not work on older versions of operating systems, you only create more problems for yourself.
Another possible issue that you need to be aware of is that you don't want your customer to be lost in a maze of autoresponders. They should have a way to contact you directly through email so that you can maintain your customer service skills. EBayers will add contact information to a direct email address and then respond with the appropriate emails and links to their infoproducts after that send them to autoresponders. This way, they have some way to contact you should they experience a problem with the download or just aren't satisfied with the product overall.