Laundromat in the hotel
 

Getting laundry done in relative comfort and at a reasonnable price is probably one of the biggest challenges of frequent/constant travel. Most hotels charge a fortune for laundry and washing your clothes in the sink might be ok for one or two items but it is hardly a sustainable way of doing things. I've always wondered why most hotels do not have a laundromat. It seems to me that it would be the most practical and economical way for many long term travelers to wash their clothes. I know that all Holiday Inn Express have one, anyone here knows if any other chain has laudromats at all their hotel?

Laundromat in the hotel
 

Timely post. My current hotel not only doesn't have ironing boards in the room - they claim not to have a single one on property. Want to press something? Bag it for laundry. First I've ever seen this

It's profitable for the hotel to charge a premium for laundry. Same reason why most hotels don't have full kitchens for guest use, treadmills in each room, or fully complimentary business services.

Research it before you stay. While most hotels don't have on-premise laundry, many do (particularly those that cater to business consultants). I've stayed at a few Hilton Garden Inns in Italy with them which has been very convenient. If your trip needs include laundry, find one with it.

Candlewood suites always have a nice laundry area right next to the workout facility and the best part about their properties is the laundry facilities are FREE, I hate having to lug around a pile of quarters.

I stayed in a Springhill Suites with a laundry room. Yes it needed change but it was great not taking home dirty laundry.

I stayed in a Days Inn with one. I do agree with the OP that laundry rooms would be a useful addition to hotels but I suspect that those who have said that the hotels would lose income by providing them.

I'd guess that they're far more common in budget accomodation.

Laundromat in the hotel
 

Hotels catering to extended stays usually have laundry rooms for guests - try Residence Inn, SHS, and Homewood Suites.

Some of these also have kitchenettes as well (RI properties tend to have full refrig/freezer, microwave and 2 burner stove).

I used to use these regularly. I still see them in some properties, of the types listed above, but they are becoming more scarce in mid- and upper-end properties.

As noted, probably due to the money making potential.

If I am planing an extended stay that will require laundry I check the hotel amenities for the location to make sure they have laundry room, if I am unsure I will call the facility first and ask what they offer and get an idea on prices so I have the correct coins/currency.
I was staying in Bangkok once and the hotel charged $3/shirt ... (there were plenty of places to go for less I didn't pay that) but I took a wrong turn one day and wound up in the parking garage and found the laundry service the hotel used ... if you dropped off the shirt yourself it was $1/shirt ... (still more then the .45 across the street)

Many La Quinta hotels have machines. I have a couple I stay at partly for this reason.^

Comfort Inns and Suites usually, but not always, have on-site guest laundry facilities. It is always listed on the website as a feature when available.

Many hotels/motels are located near (off-premises) launderettes, so one can do laundry, but at a slight inconvenience.
PS: Many of these also offer wash and fold service, you drop your stuff off and pick it up 3-4 hours later--price: $0.50-$0.60/lb, with a 10 lb. minimum (that is the going rate in Flushing, NY area.)

In the USA, most of the extended stay properties have coin operated laundries right in the hotel, including Residence Inn, element, and Hyatt House. You also tend to find self service laundries in moderately priced resorts that cater to families or in hotels that are residential in nature, where some suites might even have laundry facilities. YMMV.

I had some relatively long stays at a Fairfield Inn that had a small laundry room. When I checked in, I'd exchange a $10 bill for a roll of quarters at the front desk. I should have asked to charge it to my room for the extra points :D