I have to agree with cucaloco here, at least to some extent. Mike and I have been working up a short class for agents and investors on how to work together. So, I've been considering this question myself.
Investors act differently than retail buyers. Retail buyers ARE going to buy a house, provided they can find one they like and have their finances in order. This isn't true with investors. If an agent shows a retail buyer enough houses, they are very likely to buy one. The retail buyer doesn't know the process and the agent must hold their hand throughout the entire process.
An investor, OTOH, may know as much or more about the process than the agent. They will want more information about comps, inventory, and areas. An investor may look at 100 houses, make 50 offers and buy nothing.
Investors are often looking at lower priced houses than retail buyers. I'm not sure what the media home price is here right now, but I'm sure its higher than the $60-70K junkers I'm buying. Even at $250K, the agents going to pocket a much bigger commission than with my purchases. They're likely to do a lot more work than the retail agent. So, even if I close a deal, which Mike and I did back in May, their net proceeds are pretty small.
So, I think as an investor, you better help out. You need to do some of the leg work. Maybe that's pre-driving the properties and rejecting obvious duds. I like to use Google maps to make a map of the properties to make the viewings go quickly. When viewing, I try to take one quick look inside, and if its a dud, move on quickly. After viewing a batch of properties, we'll set down over lunch and discuss what we say. We agree on offers, if possible. If not, we'll figure out what comps we need for which properties. All offers are made electronically, so once the offers are decided, they can go in quickly. It still takes some tracking and followup.
Bottom line, I think investors and agents working together is a different relationship than agents and retail buyers. Investors are going to generate more work for a smaller payday than retail buyers. So, they have to put in some extra effort to make it worthwhile. Agents have to realize the investor is going to have much different buying criteria than a retail buyer, so many more "ridiculous" offers are going to be necessary. If they can divide the work, and can understand each other, they can have a profitable relationship.