It's more complex than that - TC's reporting isn't much better than that from the unions.<p>That part of SF Twitter is likely moving to (Market street between 6th & Van Ness) is really blighted, most business left the area some time ago except for 2-bit retailers, and it has become a skeevy dump over a 20 year period. The tax break is for companies over a certain size who lease space for a minimum of 5 years; Twitter would be one beneficiary, but behind them is SF property management company Shorenstein, who has much more to gain/lose depending on the outcome. Due to long-standing existing plans, several firms/organizations are set to move out of that area this year and next - Bank of America, the CA public utilities commission, SF county health commission. BofA is moving some operations out of town and others into vacant space in its financial district offices, the CPUC has been waiting for construction on its new HQ to be completed, SFCH is also moving into new premises.<p>The upshot of all this is that an already blighted area is anticipated to see the departure of ~8,000 employees to other parts of downtown and <i>3 million square feet of newly vacant office space</i> - which means imminent death for other local businesses like coffee shops, convenience stores and drugstores which serve the needs of office workers. Besides office workers, the only other traffic in that area comes from the Warfield (a popular live music venue), two tired-looking strip clubs, and a few discount stores selling clothes, cellphones or DJ equipment. Not only is it desperately in need of new business, it's in need of a younger population with different standards and demands.<p>Anyone who's been thinking of opening an office in SF ought to look into it; besides the possible 1.5% stock option exemption for the next 5 years, right now prospective tenants have about as much negotiating power as they will ever have. Monthly rent in that area is under $3/sqft. and although it is tatty at street level, it has the same transit connections as the rest of downtown.