Two Types of Krishna Katha! Why are they appealing to even materialistic people?

SRILA PRABHUPADA SAYS:

Krsna-katha means narrations about Krsna. 

There are two krsna kathas:  

Narrations spoken by Krsna and Narrations spoken about Krsna.

Bhagavad-gita is the narration or the philosophy or the science of God, spoken by Krsna Himself. 

Srimad-Bhagavatam is the narration about the activities and transcendental pastimes of Krsna. 

Both are krsna-katha.

It is the order of Lord Caitanya that Krsna-katha should be spread all over the world, because if the conditioned souls, suffering under the pangs of material existence, take to Krsna-katha, then their path of liberation will be open and clear. 

This Krsna-katha will also be very much appealing to the most materialistic persons because Krsna's pastimes with the gopis (cowherd girls) are exactly like the loving affairs between young girls and boys within this material world.”