Reposts are a common occurrence on the site. However, one must supply the link to the original post in order for a repost call to be legitimate. Such a call with no link will often be responded to with "link or stfu" and/or spiteful upvotes.
Legitimate repost calls will entice users to scorn the submitter for not having searched the site to see if the content was previously submitted. Responses like "you didn't even search did you?" and "found it using your own tags" are quite common on repost threads.
In rare occasions reposts can actually 'beat out' previously submitted posts.