Subleases spike in number as SF startups downsize
techcrunch.com
techcrunch.com
Another common situation is landlords happy to terminate a couple-year-old lease, because they know they can easily get a higher rate on the open market.
For sub-leases in particular, other (non-monetary) factors are important, for example willingness of the sub-tenant to vacate at certain timetables, sub-tenant palatability to the landlord, and existing prior relationships with the master tenant.
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