Using AWS DynamoDB or Redshift to store analytics data

I would like to ask which services would suits me the best. For example, an facebook-like mobile app where I need to track every movement of a user such as the pages visited or links clicked.

I am thinking of using DynamoDB to create multiple tables to track each different activities. When I run my analytic app, it will query all the data for each table (Similar hash key but different range key so I can query all data) and compute the result in the app. So the main cost is the read throughput which can easily be 250 reads/s (~ $28/mth) for each table. The storage for each table has no limit so it is free?

For Redshift, I will be paying for the storage size on a 100% utilized per month basis for 160GB. That will cost me about $14.62/mth. Although it looks cheaper, I am not familiar with Redshift, hence, I am not sure of what are the other hidden costs.

Thanks in advance!