How to find the market size, expected revenue etc. for any start up idea? for eg market size of online flash banner creator websites

I have seen many website which create flash banner ads online and you can directly download the customized flash banner, thought it is not a new business idea I feel I can add some unique feature to this business

But on the second thought I want to know if this idea is worth putting time and money, for that I need to know the market size of online flash banner ad sales and aprox estimated revenue of present players in the market. I tried to google for a long time to find the answer to it but was unable to do so.

It would be really great if someone here could give some guidance regarding how to find the market size, estimated sales etc. for flash banner ad business. Thanks in advance

I like what Will said but in Google itself I find "flash banner" WITH QUOTES results in About 7,670,000 results.

If you found sites doing that which are also selling advertising, could be a bad indicator.

But I don't understand if your business is for consumers or web designers. I'd think that entry level web designers resorting to WordPress would be a good target to consider.

I'd recommend to hire professionals for several hours/days and be sure in the results. For ex you may check this guys: singularex.com