The can kill a street's, subdivision's, community's, town's, city's, county's, state's property values pretty quickly.

If your not selling short in an area, you lose and the short seller wins.  If you built up a lot of equity or put down a large downpayment that has kept you from having to go short, the price you think you're setting "below market comparables" will be the low-water mark that any new short-seller next to you will use when setting their price.  Your time on market will be until the quality short sale properties sell out or force prices to where you now are having to sell short.  (There goes your plan to step-up).

If the bank takes too long to respond and you're working with a buyer, they may get frustrated.

Realtors have to waste time all through the transaction to follow up on the SS Dept.

SS Departments come up with ridiculous computer generated values or BPO's often above the most recent comparable sales and as such say there is no way they will accept the offer on the table.

Reduced commissions for harder work following up constantly.  (I'm not an agent by the way)

Lending programs have disappeared while SS offers were being reviewed for 4 months.

"Declining Markets" labels now make many mortgages have a minimum of 5% down at 100% financing rates and mortgage insurance.

Unreasonableness from SS Departments when it comes to commissions to agents, closing cost contributions and down payment assistance.

Short close of escrow periods.  Who do they think they are anyway?

Weird stuff such as lender accepting an offer then changing their mind and foreclosing a couple of days later

Wasted time, wasted marketing, wasted emotions, wasted energy.

Fake short sale assistance companies sprout up alongside the short sale seminar experts with 1 year experience or less, pretending to work for the sellers but actually jockeying for position with the lenders to secure relationships.

ONLY IF YOU LIVE IN A TRUST DEED STATE, READ THE The Beautiful Happy Joyful Benefits you get with Short Sales! Part 2 of 2 

****DO NOT READ IT IF YOU LIVE IN A JUDICIAL FORECLOSURE or MORTGAGE STATE (Unless you plan on moving to a "Trust Deed State") AS YOU HAVE A MUCH MORE GRUELING PROCESS!!****