Some publishers republish the same article several times a day. The titles of these republished articles remain the same or are modified slightly.
However, Viigo distinguishes between articles using their Globally Unique Identifiers (GUIDs) rather than their titles. Therefore, if the publisher changes an article's GUID and then republishes, Viigo identifies it as a new article and downloads it again. This is why you may receive the same article several times.
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