A Meta-Learning Perspective on Cold-Start Recommendations for Items
Matrix factorization (MF) is one of the most popular techniques for product recommendation, but is known to suffer from serious cold-start problems. Item cold-start problems are particularly acute in settings such as Tweet recommendation where new items arrive continuously. In this paper, we present a meta-learning strategy to address item cold-start when new items arrive continuously. We propose two deep neural network architectures that implement our meta-learning strategy. The first architecture learns a linear classifier whose weights are determined by the item history while the second architecture learns a neural network whose biases are instead adjusted. We evaluate our techniques on the real-world problem of Tweet recommendation. On production data at Twitter, we demonstrate that our proposed techniques significantly beat the MF baseline and also outperform production models for Tweet recommendation.
This is an interesting and well-written paper but there are some parts that are not well explained, hence my recommendation. These aspects are not clear:
1. I am not sure about the "meta-learning" part. The recommendation task is simply formulated as a binary classification task (without using matrix factorization). The relation to meta-learning is not convincing to me.
2. "it becomes natural to take advantage of deep neural networks (the common approach in meta-learning)" - this is not a valid claim  - deep learning is not the common approach for meta-learning; please see the papers by Brazdil and also the survey by Vilaltra & Drissi.
3. What is the input to the proposed 2 neural network architectures and what is its dimensionality? This should be clearly described.
4. I don't understand why in the first (liner) model the bias is constant and the weights are adapted and the opposite applies for the second (non-linear) model - the weights are fixed and the biases are adapted. This is an optimisation task and all parameters are important. Have you tried adaption all parameters?
5. The results are not very convincing - a small improvement, that may not be statistically significant.
6. Evaluation
-Have you sampled the same number of positive and negative examples for each user when creating the training and testing data?
-How was the evaluation done for items that were neither liked or disliked by a user? 
-Why are the 3 baselines called "industrial"? Are they the typically used baselines?
-Is your method able to generate recommendations to all users or only for some? Is it able to recommend all new items? In other words, what is the coverage of your method?
-It will be useful to compare you method with a a pure content-based recommender. Is any of the beselines purely content-based?
7. Discuss the "black-box" aspect of using neural networks for making recommendations (lack of interpretability)
These issues need to be addressed and explained during the rebuttal.