Algorithm
A set of rules or instructions designed to perform tasks, such as sorting products, pricing, or determining the visibility of items. For resellers, platform algorithms and design govern many essential mechanisms on the platform, such how listings are displayed to potential buyers, or how content is moderated on the platform, making them crucial yet opaque factors that shape work in online marketplaces. Although resellers and other secondhand workers often talk about gaming or beating “the Algorithm” of a given platform, they usually mean the combination of algorithmic and design features characteristic of that platform. These algorithmic features are usually complex, opaque to platform users and ever-changing, making these strategies hard to verify. Moreover, it is crucial to remember that algorithmic systems are created and maintained by humans who decide on what features and outcomes to prioritize.

Algorithmic Bias
Refers to the prejudices or favoritism embedded in platform algorithms, often leading to uneven opportunities or burdens for certain groups of people. Algorithmic bias in reselling can affect which items or profiles are promoted or demoted in visibility, influencing sales performance and replicating social inequalities.

Algorithmic Governance
The management and control of human activities through automated systems and algorithms on platforms like Poshmark or eBay. Algorithms mediate things like post and account visibility, pricing, and even account suspensions, often in opaque ways (to the users). Like other users, resellers must constantly adapt to these rules, which significantly shape their business strategies and outcomes. Researchers of platform work have developed related terms to describe how algorithms, and more broadly, platforms, create mechanisms that ‘manage’ and influence workers (algorithmic management, platformic management).

Algorithmic Opacity
The lack of transparency around how algorithms operate. In reselling, algorithmic opacity means sellers often don’t know why some posts/items are promoted more than others, leading to frustration and a sense of confusion in navigating platform rules.

Automation
The use of technology to perform tasks with reduced or hidden human intervention. In reselling, automation tools (such as bots) can assist with cross-listing, managing inventory, or customer communication, but are also regulated by platforms. Remember the term ‘automation’ is not ‘black and white’ since many digital tools involve various kinds and levels of automation. The ways a platform defines what constitutes automation, is also the way the platform moderates its use via rules or technical means, affecting secondhand workers labor.

CAPTCHA
A security mechanism often encountered when logging into or interacting with platforms and websites. These often involve logical or visual puzzles and clicking boxes to ‘prove you are a human’. On platforms like Poshmark, CAPTCHAS are used to curb automation use, resulting in additional click work for resellers. Bots can sometimes use CAPTCHA solvers, which rely on remote workers solving these puzzles for very little money.

Gig Work
Temporary, flexible jobs often mediated through digital platforms, where workers are paid per task or project without a relationship of traditional employment with the company. Resellers operate outside of traditional employment protections, navigating income instability and platform control over key aspects of their business. Note that the IRS classifies reselling a s kind of gig work.

Image Processing
The use of AI tools to automatically enhance, recognize, or sort images. One tool which is essential to resellers based on image processing (and large datasets of entries historically generated by users like resellers) is Google Images. Reselling platforms often use image processing for visual searches to make suggestions for listings and identifying counterfeit products. This may help streamline operations but can also introduce errors. These systems can disproportionately harm people from marginalized groups given the biases in datasets and biased decisions of the engineers. For example, it could result in penalizing resellers with darker skin color.

Information Asymmetry
A situation where one party has more or better information than another. In reselling, platforms gather data about customers, sellers, behaviors, and inventories, having visibility into patterns of use which giver the platform more control and power over all parties. Additionally, information asymmetries also arise from the ways platforms build their technical backends, with algorithmic and other mechanisms mediating interactions on the platform.

Moderation
The control over the users behaviors on the platform by human and automated means. This includes reporting of counterfeit items or inappropriate behaviors by other users, the platform’s regulation and control of bots through technical means and actions on users, and the automated detection and decision-making on cases by algoirthmic systems. The use of AI to automatically monitor and enforce platform rules, such as detecting prohibited items or inappropriate listings is a hot subject of research which platforms currently consider as ways of leaning their moderation efforts and human labor. Automated moderation in reselling helps platforms manage large volumes of content but can lead to errors, penalizing resellers unfairly or inconsistently.

Platform Work
Work that is mediated by digital platforms, where resellers operate under specific rules, algorithms, and interfaces that govern their interactions with buyers, suppliers, and the platform itself. Resellers rely on platforms for visibility and transaction management, but also face challenges like fluctuating fees, algorithmic changes, and platform governance.

Recommender Systems
Algorithms designed to suggest products or listings to buyers based on their browsing history, preferences, or other data. For resellers, recommender systems are vital as they determine how often and to whom their items are shown, thus directly impacting sales. Note that recommender systems also interact with the user interface and default settings. On Poshmark, the importance of sharing is due to the default ordering setup which is “last shared”.