A lawyer and a doctor are exchanging small talk at a cocktail party when another party-goer interrupts and says, "Excuse me, Doctor, but I haven't been feeling well. My nose is stuffed up and I ache all over."

The doctor replies, "It's probably just allergies. Take a decongestant and some aspirin. If it doesn't get better in a few days, call my office for an appointment."

Seemingly satisfied, the party-goer strolls away.
The doctor turns to the lawyer and says, "It really bugs me when people come up to me and ask for free medical advice. Do you think I should send that person a bill for my services?"

"Yes, I do." says the lawyer.

The next day, the doctor sends the party-goer a bill. And, the lawyer sends the doctor a bill for consulting fees.