The disclosed subject matter relates to a system and method for selecting/recommending ads based on a contextual bandit approach. The disclosed approach leverages various embedding vectors of item, search, page taxonomy trained based on traffic data via advanced deep learning models, and uses model signals (e.g. historical CTR, item price, rating, quality) from other ad placements. The learning mechanism on top of the current methodology to automatic chooses the best feature sets and adjust model performance over time. The contextual bandit model performs better with respect to CTR than the Thompson Sampling model, and achieves lower regret and faster convergence over time.