While we're chiming in again, I'll add that real estate practices vary widely in different states. What is standard practice in PA may be foreign to practitioners in other states.
A realtor in California might stress the importance of square footage; if a seller there said he didn't know the square footage, buyers might be suspicious. (Just an illustrative example; I've never worked in CA.) In Pittsburgh, nobody cares about square footage (except for commercial property), and most sellers don't know exactly how big their house is.
Compensation practices vary as well; each state has different corporate tax rates and puts different regulatory burdens on brokers. License law in each state may further constrain acceptable compensation. RESPA in PA bans any compensation except for real estate services (e.g., you can't get a referral fee for recommending a home inspector or appraiser or home warranty). All these factors influence what works and what doesn't in each state.
In addition, each company has its own compensation policies. Full service brokers in Pittsburgh generally charge a flat administrative fee as a closing cost (to everyone in most cases; buyers aren't singled out to pay extra).
Commissions are (by state law) always negotiable -- but agents are still subject to company policy. Even if the starting commission were 8%, the buyer's agent would often get 2% (splitting it 4 ways between two brokers and two agents) to start -- minus MLS and other fees. Then we get taxed on the income, of course. In the end an 8% commission might yield 1.5% actual take-home pay to the buyer's agent -- and commissions are hardly ever 8%!
In any case agents can only cut their own personal commissions -- not the broker's or co-broker's. If the broker has an internal minimum commission of, say, 6%, you can always list for 5% -- but the broker may deduct the difference out of the agent's hide at closing. (They'll take what their share would have been had you listed at the minimum, and give you what's left over. A $100K house at 5% would be a $2,500 commission for the agent, ignoring taxes and fees. Under a minimum commission policy, the broker would take $3,000 (1/2 of 6%) and give the agent $2,000 -- as if he'd listed at 4%.)
Same goes for admin fees. If the buyer refuses to pay, the agent can still take the business -- but some brokers will dock the agent's commission at closing.
My point is it's more expensive than it may appear for agents to cut commissions (which is what waiving a broker fee amounts to), and it's incompatible with agents running a successful business and providing full service.
The definition of "full service" varies as well. I cater agent tours, check up on vacant properties (once discovering a gas leak!), weed whack / mow / remove dead squirrels before showings, make appointments, then wait around to let in inspectors and contractors, pour antifreeze down drains if the power goes out, etc.
As Rebekah says, you get what you pay for!