Online social networks (OSNs) have changed the way of how people interact; however, lately, people are questioning more and more their business models. During the last ten years, new solutions based on decentralized architectures have been proposed, namely, decentralized OSNs (DOSNs) and blockchain online social medias (BOSMs). DOSNs were introduced several years ago and their main goal is the preservation of the privacy of the users in such a way that the data and the content of a user are always under their control. BOSMs leverage the usage of blockchain either to enforce the privacy of the users or to redistribute the wealth generated by the platform through a rewarding system. Steemit is the most stable and well-known BOSM with more than 1 million registered users, where users can create their own social network by following other users. To the best of our knowledge, no study exists on the relationship between the economic and social characteristics of BOSMs and on the way the rewarding system affects the social activity. The main goal of this article is to evaluate the characteristics of the Steemit follower-following graph to understand how the social and the economic aspects of BOSMs intertwine and influence each other. We study the properties of the Steemit follower-following graph and a few selected hotspot contents. The analysis shows that users are highly encouraged to be socially active, especially producing content, but the richest users are not also the most social ones, which suggests us that users can get rich without much involvement in the platform, using external mechanisms.

Since their introduction, Online Social Networks (OSNs) have transformed the way people interact with each other. Lately, a new trend is rising in the development of OSNs, fueled by an increasing interest of the blockchain technology and the benefits it can bring to the world of OSNs. Blockchain Online Social Media (BOSMs) are Social Media applications that are supported by the blockchain technology. Thanks to a blockchain, BOSMs either try to enforce the privacy of the users or try to redistribute with their users the economic wealth generated by the platform through a rewarding system. There are countless BOSMs available which incorporate a rewarding system. Among them, Steemit can be considered the most well-known platform exceeding 1 million registered users. Steemit is supported by the blockchain Steem, which is a blockchain that natively supports the development of social applications by the usage of transactions that model social activity. Even if other important blockchains, such as Ethereum has been widely analysed, at the best of our knowledge, no study exists concerning the topology of the transactions graph of Steem. The main goal of this paper is to study the structure of the Steem transaction graph to understand its characteristics and unveil crucial knowledge concerning their users. More in detail, we build the Interactions Graph and, after its study, we evaluate three subgraphs that capture its social and monetary aspects. The degree distributions of the graphs follow a power-law. Additionally, we detect a substantial number of bots that offer paid services on the platform among the most active users. Lastly, the investigation of the four analysed graphs through a bow-tie structure, suggesting that half of the users have a passive social behaviour and that 80% of the users tend to accrue economic value

Non-fungible tokens (NFT) represent one of the most important technologies in the space of Web3. Thanks to NFTs, digital or physical assets can be tokenised to represent their ownership through the usage of smart contracts and blockchains. The first generation of this technology, called NFT 1.0, considers static tokens described by a set of metadata that cannot be changed after token creation. The static nature prevents their wide spread as they do not support any meaningful user interaction. For this reason, its evolution, called NFT 2.0, has been proposed to make tokens interactive and dynamic and enhance user experience, opening the possibility to use NFTs in more ways and scenarios. The purpose of this article is to review the transition from NFT 1.0 to NFT 2.0, focusing on the newly introduced properties and features and the rising challenges. In particular, we discuss the technical aspects of blockchain technology and its impact on NFTs. We provide a detailed description of NFT properties and standards on various blockchains and discuss the support of the most important blockchains for NFTs. Then, we discuss the properties and features introduced by NFT 2.0 and detail the technical challenges related to metadata and dynamism. Lastly, we conclude by highlighting the new application scenarios opened by NFT 2.0. This review paper serves as a solid base for future research on the topic as it highlights the current technological challenges that must be addressed to help a wide adoption of NFTs 2.0.

Web3 is progressively decentralising Internet services with the introduction of the blockchain, from social networks to online trading. Filecoin is a Web3 storage marketplace implemented on top of the Interplanetary File System that aims at decentralising storage by rewarding users who pledge storage to the system. Clients form deals with storage miners, who store deals on the Filecoin blockchain for transparency and auditability. Storage miners can also obtain extra rewards when they mine a block. In this paper, we show that although Filecoin aims at complete decentralisation, the rewarding system acts as the opposite. We download a dataset composed of 47.5M messages and expose that most of the blocks are created by the same storage miners, who are also the ones that pledge more storage. An analysis of their identity shows that they belong to cloud companies, that have a lot of extra storage resources. The effect observed is due to the fact that storage miners are able to commit all extra storage to the system, even when there are no deals in them. Additionally, this effect is further intensified by recent updates to Filecoin, which let storage miners update committed storage to deal-containing storage effortlessly.

Online Social Networking platforms (OSNs) have become part of people’s everyday life and their usage covers the deep-rooted need for communication among humans. During recent years, as people are questioning more and more OSN service providers, a new generation of proposals, based on blockchain became very popular thanks to the ethics adopted by these platforms. Steemit is the most important blockchain-based social networking site, which integrates, as main novelty an economic layer to the social media service. Steemit is implemented on top of Steem which, as in other blockchains, awards miners of the blocks with cryptocurrency. Steem miners, called witnesses, are not chosen based on the solution of a mathematical problem, as in Proof of Work based systems, but must be voted by other users. In this work, we decide to study the witnesses on Steem and their contribution to the social platform Steemit, and their social impact. We performed a set of analyses to shred light concerning their behaviour and to understand how they are socially perceived by other users. Analyses show an important social impact but, at the same time, some of them have a negative social impact. Their discussion is polarized towards content concerning Steem, Steemit, witnesses, and other platforms hosted on Steem.