In high-frequency trading, arbitrage is widespread both in traditional finance and in cryptocurrency markets. However, little research has examined it in digital collectibles. Opportunities arise from offers on multiple markets for similar collectibles. For example, a collectible trading card is bought on market A and sold at a premium on market B. This might affect the less sophisticated consumer buyer. To investigate its impact, an empirical analysis of historical arbitrage in non-fungible token (NFT) markets on the Ethereum blockchain was conducted. Using data mining, over 26,000 Ethereum transactions were identified and enriched with market data, including Ethereum price, trading volumes, and network transaction costs. Additionally, the correlation with blockchain-specific trading phenomenons such as maximal extractable value (MEV) or the broader decentralized finance (DeFi) ecosystem is tested. The study reveals that NFT arbitrage is a lucrative yet competitive sector, contributing to less than five percent of the total MEV profits of trading bots on Ethereum. In total, a small group of approximately 150 trading bots dominate NFT arbitrage, generating around $3 million in profit over the course of three years. The profit distribution is highly uneven, with a few bots earning the majority of the profits. External factors like Ethereum gas prices and total MEV profits present no statistically significant impact on NFT arbitrage profits, while a significant correlation with NFT trading volumes is noted. Finally, case studies examining how inefficiencies occur, establish a basis for understanding market dynamics in the developing NFT landscape.