Information regarding Spark pakage of marketo

I want to create the webhook in marketo  site that will send me the event data to the client which is listening when ever the lead is created in the  marketo.

as  per my research goes user should be admin .

I was going through the marketo  documentation  i come across two interesting points,

1.Not all customers have purchased this functionality

2.You can't create a custom service if you have the Spark level of Marketo.

so does customer has to purchase the webhook as a separate functionality, or it is default bundled with the packages taht customer will purchase.

2)what do you mean by spark  package in marketo , does this user will be able to create the webhooks in marketo.

Thanks and regards,

Chethan