Maybe hire a freelance market researcher to find out? ;) Generally, something like this is going to appeal to fortune 500 companies. Smaller companies and entrepreneurs are going to be doing market research themselves. From the question it is difficult to tell if you have come into possession ...
If your market is 'market research' then you can easily top € 1BN in EU alone. If you're creating a new market then to calculate total addressable market I'd look at similar products and multiple their price x number of prospects, or calculate the financial cost/upside for your prospects x number...