Struggling Wt Revenue Model for Online Job Portal Business

Hi all, I am currently building a revenue build up model for an online job portal / online start up with a business model similar to Monster Worldwide, LinkedIn, Bayt.com and WSO to an extent as well. I need to size up the market first, and create projections for revenue from employers, and revenue from job seekers (Screenshot attached).

I haven't done this before, and my googling has let me down to. Can somebody please pass me on a few tips on how could I approach this? I would really appreciate it. Thanks!

PS - this start up is asia based, and limited sources of data is an issue here....