This is the 14323rd most frequent Spanish word.
venderle
"Venderle" means "to sell to him/her/you."
'Venderle' refers to pitching or promoting an idea to a specific individual ('el inversor').
Si Juan puede convencerte, podría venderle la idea al inversor.
If Juan can convince you, he could sell the idea to the investor.
Here, 'venderle' is used to indicate selling something ('el auto') to a specific person ('el cliente').
El comerciante busca venderle el auto al cliente.
The merchant seeks to sell the car to the client.
'Venderle' is describing the action of attempting to complete a sale ('el producto') to someone unspecified ('le' represents the person).