In short, your South African guest speakers or you next guest speaker needs to be entertaining, informative and skilled, but mostly, needs to put on a  show that will hold attention while imparting important message to your audience. Motivational guest speakers have to customize presentations and fit in with you overall business objectives for the particular event of sales conference. However, the trick is to not actually to rely on your S.A. guest speakers in order to deliver a good event or function. This is ultimately your responsibility as management of the organization, not even the accountability of the PCO or event planner. Your guest speaker selection is of paramount importance, but if they are the only thing that is of good quality and exhibits any levels of professionalism, all that will be remembered is them, and not you the host or the professional event organiser. Do not allow your own event and your objectives to be over shadowed by your primary guest speakers in South Africa. They go back home or move on to other clients, while you are still accountable for targets, performance and business goals. By relying on them for bang on your buck, you are allowing them to in fact use your event to market and promote themselves and leaving you in the unfortunate situation of actually giving someone money to market themselves to your audience. You need to make sure that your event is the memorable thing, with the Pretoria, Durban, Cape Town and Johannesburg guest speakers maybe as one of the highlights... without good planning you run the risk of only the guest speaker being remembered!