I don't see any reason one couldn't have a lifetime online romance and feel fulfilled but I just want to mention I do feel there is a difference once it's moved from online to real life and in my experience, anything I've moved from online to real-life didn't work out. But I feel a strictly online relationship is absolutely acceptable especially if you're the type of person that doesn't do well with the pressures of in-person interactions and I think it could even be a healthier form of a relationship than some people may be able to obtain in person.