The use and popularity of online auctions is growing all over the world. Bidding strategies are important because they are related to an auction's final price and ultimately its revenue. This study investigates the bidding strategies adopted by online bidders and the factors of the bidders, including bidding motivations, time availability, bidding experience, and risk aversion. We use the data from China to test the model and identify three bidding strategies in single-unit auctions: agent bidding, snipe bidding, and ratchet bidding. By running logistic regression, we find that hedonic motivations, utilitarian motivations, time availability, bidding experience, and risk preference all influence online bidding strategies. We also conduct pairwise comparisons of bidding strategies based on these factors and a simulation experiment to compare the benefits brought by different bidding strategies. We conclude by discussing the implications for both research and practice.