Yes, there are online cash buyers. The key is to find em all or have them find you!!! There are MANY techniques to finding buyers for your property, too many to mention. There are many free resources online to learn how to find them and there are many expensive programs that promise to show you how to find them. Not sure if the programs are worthwhile or not but I have sold properties to online buyers myself. I believe it is a "they find you" more than a "you find them" situation, for the most part. It just depends on where/if they are looking for properties and find it.
I am always looking as well so it will be interesting to see what gets posted here. I hope some people post things that they have actually tried!!! I may start a post myself about something similar to have everyone post their ideas that way we can all learn from it!!!!!