When joining a party you will get one/some random girls for your phonebook. The quality seems to depend on the price of the party. (Watch the girls participating on the providers girls list.)
Throwing a party needs alcohol, drugs and girls. The more you invest, the more you get.
You should not be greedy and bribe the local police with 95%.
You can join your own party for free (same results as above).
During the time your girls are not available for other jobs (massage parlour for example).
You will get money, phone numbers of girls(random) and clients(random) at the brothel.
