The question addressed is whether, in connection with education, Twitter can be considered both a communication centre and an affiliation space, where virtual communities with shared interests are formed. The 6654 tweets containing the "#education" or "#educación" hashtag sent on specific days in 2014, 2015 and 2016 defined the sample. The design was a combination of the quantitative and the qualitative. The results indicated that, when tweeters not directly related with education show interest in the topic of education, they do so exclusively during a limited time period; that is to say, no permanent interpersonal links were observed amongst such tweeters. Therefore, the conclusion was that the "#educación" and "#education" hashtags make it easier to share information and to make primarily non-activist comments related with education; furthermore the hashtags enable the creation of a virtual community of shared interests but do not lead to the establishment of a permanent community. In addition, the characteristics defining the Twitter network (speed and immediacy) were observed to promote monologues more than dialogues and to encourage information sharing more than any real intention to interact or conduct in-depth discussion. These points must be taken especially into account in education.