PCOs can typically work as consultants for academic and professional associations.
They usually provide full service management for conferences including conference design, abstract management software, program development, registration, site and venue selection and booking, audiovisuals, IT support, logistics, leisure management, marketing, printing and web services, sourcing speakers, funding, sponsorship and exhibitor sales, financial management and budget control.
They tend to focus on limited areas such as destination management.
The UK is ranked second behind the US for global market share of conferences.
Thus, although there is no one source of global statistics for the conference market it appears that PCOs play a central role in several billion dollars' worth of revenue generation worldwide.