How do travel agents make money...?

... with Expedia, Orbitz, Travelocity all competing for traveler's money, how is it that travel agents make money? Also, do they take a part of the $ they charge their clients or do the airlines and hotels pay them?

Travel agencies will charge a fee for issuing standard airline tickets because the airlines no longer pay them a commission. However, the big agencies have consolidation contracts with carriers for bulk rates (mostly on international travel) and those are the tickets on which they can actually make money.

Agencies do get commission from hotels, rental car agencies, tour companies like Apple Vacations and cruise lines. Group travel can be a good source of revenue provided the agents are experienced.

They get paid by the companies they work for, which are, in turn, paid by the airlines and hotels, tour companies, etc.

And, in fact, since the Internet can help people find their own travel arrangements, many travel agencies have closed their doors...so they aren't making much anymore, overall.

They used to get their pay from the airlines/hotels/cruise lines that they booked for you. That changed a number of years ago, and now they put a surcharge on tickets they get for you.