Opening Store or Promoting Ecomm through Network?

Hey guys,

Thinking of diving into e-commerce and it seem like the majority of the talk on STM is about running eComm through a self-owned store (ie Shopify). On the other hand, there are much fewer threads about running ecomm offers from performance networks.

Wondering why that is and if you guys would recommend one approach over the other for a complete noob. What are the pros and cons of each? Am I comparing apples and peaches?

Thanks