The market for online advice is large and growing, and there are certainly opportunities to take your share of that.
So I prefer to give an encouraging answer, and would recommend developing a new platform for a niche knowledge area, a specific language or geography, or a specific profession.

And when you are successful and you have secured a certain market share within the market you have defined, one of the large players may decide to acquire your business!

Back to your question. How to size such market? Well, different professions are at different levels of the digitization game. While business consultants who target startups may operate in a highly digital and online business landscape that includes Clarity, others (such as let's say lighting designers) still have a lot of papers on their desk and visit clients in person - and they see it as the only way to be successful. What I am saying is if you could decide whether you want to be the follower who does things more efficiently or the pioneer in a new market will also help you to decide where you will operate.

Let's take a look at a fictitious example. You want to serve people seeking architectural advice so you recruit experts who are building architects, and in order to make sure they are qualified you require AIA membership (AIA is the professional architecture association). There are more than 90,000 licensed members of the AIA and I can tell you for sure nearly none of them gives online advice. So if you develop a platform aimed at the specific needs of that market (the ability to share drawings online comes to mind) and 10% of the membership would join each selling 3 hours on average per week, then you are talking about a market volume of almost 1,5 million hours per year. I guess they sell at $100 per hour and you take 20% so your share in the turnover - in this example - would be $30MM. You can put different numbers in the equation to calculate the volume based on different pricing or engagement percentages.

Sounds unlikely? Not if you prepare yourself well, find a market with a real need, communicate and deliver a clear customer benefit and offer good support. And - of course - you've got to create a service that really adds to the current relationship between the two parties you match. Would you reach these numbers the first year? Of course not, but how quickly you do reach them depends on your character as an entrepreneur, your desire and ability to work hard and be disciplined, the need for your service in the market you target, and your social skills and ability to secure funding.

If this got you interested, let's schedule a call at any time convenient for you. A 15-minute conversation will surely create a lot of insight!

Good luck,
Rogier