Is this plagiarism or competition?
tokenadult: My thought is that you haven't described the situation very specifically, but if you came up with an idea for a website with Feature Set {item1, item2, item3, . . . } and did all the coding yourself, you aren't plagiarizing anybody. You're just attempting to solve a problem someone else is attempting to solve too. The users will decide whom to do business with.Trademark and copyright are distinct issues, but you haven't mentioned anything that would raise a trademark or copyright issue.