Forecasting - Review Volume & Average Rating I just want to confirm -

*

*our review volume has an upward trend but no seasonality. I can use holt's exponential smoothing. Right?

*for average ratings, no trend, and no seasonality. simple exponential smoothing?

Are there any other factors I should consider? Thank you!

Yes to both your bullet points.
"Any other factors": I would strongly recommend not using your own gut feeling in choosing a model, but to use an established forecasting package. In R, there are the free forecast and fable packages, both the gold standard in general forecasting. They of course also include exponential smoothing, in a more sophisticated state space framework. I also very much recommend this free open textbook on forecasting, which was written by the authors of the R packages and serves as a wonderful complement to it.
