It truly depends in the market. The rental market is very competitive right now and I would find that both parties might be paying a fee. You can find more helpful hints on my blog on my website.
However, as in all real estate transactions, everything is negotiable. You could be in an area where the landlord has, historically, always been the one to pay the fee. But if any individual landlord insists s/he won't pay the fee, then the responsibility falls to the tenant. In such a situation, the tenant would factor in the extra cost and, if the property, terms, and total cost were still desirable, they should have no problem justifying it.
1. Landlord pays
2. Landlord splits
3. Tenant pays
Often the landlord will begin by trying to push the commission back on the tenant and change his posture if necessary to be competitive. It is wise for the landlord to do what is customary or stand to lose a tenant as a result. And so if competing rentals offer "landlord pays commission" it is wise to do the same so as not to disincent a prospective tenant.
You can negotiate this point, may or may not succeed, but you certainly can try. So if the landlord is not paying or only paying a portion, then you can try to push back if you lease is strong otherwise.
Good luck to you,
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Basically, if the demand for rentals in the area are so great that the landlord can get away with not paying the fee and tenants just flock to their units ... then that is the way it happens. If the market is such that the landlord needs the marketing skills and attention of a professional real estate agent to attract tenants to their unit ... then chances are, the landlord will be paying the broker fee.
My guess is in Sudbury, in this current market, is that the Landlord will pay the listing agent fee and a tenant will be pay his/her own finding broker's fee ... commonly known as 50/50. Good luck!
Your local Realtor can advise you. But, it's all negotiable.
Hope that helps.