Very Poor Service.
When I called to inquire about renting a table and chairs for a party, I was informed by Charles at SF Party that we couldn't talk about availability or delivery options before he took my personal information including credit card number. After spending 5 minutes setting up my "account," Charles said that delivery of my order wasn't available at all because it was under the minimum order. What a backwards way to conduct business.
A good place for variety.
This place is pretty big and it has variety ranging from bachelorette/bachelor party supplies, children supplies, and all sorts of theme parties for other occasions. After buying here several times, I would say that the customer service is inconsistent but generally okay. Sometimes they are short staffed or seem to be busy with other things. I'd say the prices are probably the best in San Francisco.