A Master Protection Agreement is an extended warranty offered by Sears stores on certain electronics, appliances, and hardware. Essentially, it covers anything that could happen to it (in theory) that isn't normally covered by the manufacturer's limited warranty.
For instance, say you buy a Sony video camera, and are on the beach frolicking around, when you get sand in your camera. Normally, Sony would laugh at you and ignore your puny request for a new camera (as sand tends to do very bad things with electronics). Sears, on the other hand, if you bought the Protection Agreement, will happily fix your camera, and if they aren't able to get it into any sort of working order, will give you a new one at no extra charge.
Sears also has various clauses in there for your benefit, such as a no-lemon clause (if the product breaks 3 times in a year, they will replace it), free once-a-year preventive maintenence, and free once-a-year cleaning.
At least on paper.
In practice, MPA service is spotty at best. The part of Sears that handles such claims (not terribly sure of the name, but it is a dark and mysterious sub-organization to us humble salesmen) will usually give you the run-around, trying to fake out some sort of psuedo-agreement on fixing it. If you're persistent, however, Customer Relations (another mysterious agency within Sears) will step in, slap the MPA department around a bit, and give you what you need.
At least in Electronics, MPAs usually come in either one through five year agreements. Some can be home agreements, which means they come out to your house and fix the thing, rather than you hauling the piece of junk in yourself. This is best for big-screen TV's.
What you should buy MPAs on:
1) Primary televisions (ones you use all the time)
2) Video Cameras (all types; those things are fragile)
3) Expensive home theatre systems (Bose, Denon, etc.)
4) Anything considered an important investment
5) Cheap stuff (why, you ask? Because if you buy it, and it breaks, they will give you a new one, free, as many times as is needed before you get one that works. A five-year agreement at 500 dollars sounds like a bargain after your television melts three years after use, because you're getting a new television.)
What you shouldn't buy MPAs on:
1) Sylvania televisions (the MPAs are usually as much as the TV itself)
2) DVD players and VCR's (come on now)
Sears calculates how much an MPA costs by some archaic formula, but it basically boils down to how much the average cost is to fix them. As a result, cheap televisions usually have MPAs that would almost double the price. Not worth it.
Be prepared to get a sales pitch. Sales associates working at Sears live and die according to how well their protection agreement performance is. If it's too low, they get the axe (I should know, I currently have the lowest percentage in the department, and my job is constantly being threatened). If it's high, they get alot of back-slapping and perks (parking spots, food, awards, etc.)
Why? There are several reasons why Sears take these things so seriously.
For one, it is essentially pure profit for Sears. Most people that buy these things forget about them four or five years down the road, and hence never use them. That equals to pure profit for the company, as they just made you plunk down another 100-500 dollars for a service you won't even use.
For another, managers get hefty bonuses depending on whether or not their department/store does well in MPAs. In fact, our store manager just came back, healthily bronzed from the Mexico sun, due to our performance in agreements last year. If you bring down the average, you're gonna get canned, because after all, Mexico is more important to the manager than you paying for college or putting food on the table.
For another, more basic reason, Sears needs the money. They've been losing market share to Walmart, Lowes, and any other retailer for the last couple of years. People are defaulting on their credit, the company is being investigated for investor fraud, and their prices are constantly being undercut (even though they do price-match). Protection agreements are probably one of the few things keeping the business solvent at this point.
See also: Replacement Agreement, Sears