Verified answer

I've been a flash animator/web designer for around 6 years and the best way to make reoccurring revenue through flash is to charge people monthly for website updates. Animations themselves don't make much money unless the series becomes very popular and you can sell merchandise. And even then, people will forget about the animation with time. The best thing to do is to make a website (which you can sell people really basic flash websites for upwards of 800 dollars) and charge them 20 bucks a month for updates whenever they need it, or more depending on how many updates the people need. It doesn't seem like much but when you start managing 50 websites, 50 times 20 dollars a month is a lot of money coming into your pocket with no overhead costs.

It can be hard to get a following. YouTube is a good place to get revenue, but you have to build the following, before you get any money. It often helps to get mentioned by popular people, make videos about what's popular, but it's luck more than anything. Most artists are struggling ones, unfortunately.

Try the website idea if you can!