Should an investor buyer use an agent for on market deals?

[Travis Reed]

I am not very creative at looking for off market deals and generally spend most of my time looking at new zillow listing. I save my buy box properties and if they get 30+ days old I make an offer. I usually call the listing agent if the info is available and make a verbal offer that way. In my mind, if I use the listing agent he will be more motivated to sell the offer to the seller. Is this a good approach or am I missing something with using an agent? 

As time goes on I do intend on having some agents in certain areas send me deals they find and I will of course use them on the deal if they are the ones that brought it to me.