This group is the reason why your IXP even exists and they really need to be properly catered for. Your participants are at your exchange because they want to peer with other ASNs and it is important that you provide them with the necessary information and tools to allow them to do this. Furthermore they need to be able to contact you and any third party colocation facilities and this information must be quick and easy to find.
Your participants value the uptime of your exchange and one can make them feel at ease by displaying graphics, statistics, network topology maps and other information about your IXP. Lastly they need to be kept up to date with any developments at your exchange such as planned maintenance on the IX infrastructure, new participants, new colocation facilities, general and technical meetings etc. Therefore one needs to make this information clearly visible and easy to reach.