i think if you wanna register as as IB you do not need any negotiations, but if you wanna open a white label, negotiation is needed.
an IB is more like brokers marketers, marketing brokers brand and get paid by commisions
but as an IB you can negotiate with them for special treatment , for example, CPA+revenue share scheme, margin P/L scheme ( deposit minus withdrawal),deposit bonus scheme,education scheme, and etc
But usually before a broker can support your request , you must give broker proof if you can deliver your promise ( like attract a lot of clients, or margin deposit requirement,lot requirement), if you can deliver it i am sure they will give anything that you want,
i remember i have an IB friends, who cleaverly promoting his brand new IB with contest.
he held a trading contest for 2-3 months, with amazing prize (total prize price around $2000) and he had calculated all his risk, and buy the prize with credit card.
after that he promoted his IB aggresively. and got many contest participants, in the end of contest, he was in profit .
i think the same tactic can be used if we wanna negotiating with brokers, reach the higher IB level like Instaforex Scheme, or we participating in IB contest like Tickmill Grand IB contest