I work in K12 public education in the states. Free or not, there is a LOT of competition for platforms that supposedly solve a problem for schools. In truth, most rarely do. Why? Because the "problem" being solved isn't always seen as a problem; the districts may already have a solution that is working and is low-cost or free, therefore the districts will not see a need to "fix what isn't broken"; as mentioned above - if ad-supported, you will not find many (if any) schools in states signing on because ads are a VERY tricky prospect in public schools on websites.
If your sales are based on ancillary sales, the issue you have there is sheer interest. For example, if your site sells items based on student artwork (a la artsonia.com), you are relying on friends, family and the occasional stranger to click through and buy the items. That's a tough model to break into unless there is an incentive to the schools and/or students.
You have yet to state what your platform is or what it supposedly solves. That alone will give pause, though I understand not wanting to show all your cards if things are in the early stages.