You write, what's more to say about that? Nothing, right? Wrong.
There are a few ups and downs to writing on another site after being contracted, one being you can't use the same account to write on another site, because legally, that one site owns all your books- even if you start a new one.
An up is you don't get bothered much by other companies looking to recruit you, a down to that is the company might be better than the one you're currently on.
But chances are if you're contracted to that site then it's probably the perfect one for you, you've most likely done tons of research on it and its rival companies and found that that site was the best for you.
That, or your like me and found one site, liked reading on it, decided to write on it, and later found out of its rival companies, did research, and you either a) were too lazy to move your content to your better website; or b) this was the perfect site for you. In my case, b.
New novel companies come in all the time, though very few grow to become as big as Webnovel and Wattpad and a few others.
Now, if you really wanna try and write on another site after you're contracted, you can make another google account or use one if you already have one. You could start new and write on that site with your alt account.
You could become extremely popular with that site extremely quickly and have a good, steady reader base. You might be compelled to sign a contract with them, but then you'd have two stories on two different websites to keep up with, including characters, plots, settings, and all.
It's easy for me to keep up with two stories (barely) because I 1, only post on one site, 2, don't post as supposedly 2 different people, and 3, this has no characters, plot, or anything else that makes up a book, this book does have a goal though, to teach amateur writers (or not-so-amateur writers).
One more thing before I end today's chapter, think before you sign.
Alright, have a good day, hope to see you next Monday. Write a handful of chapters for me, will you? (If already have an in-progress book, if you don't create a short story for me) Bye!