YouTube is very different from Facebook, Twitter and Instagram. The fact that you can only have video content there makes the frequency of posting much more time-demanding than writing a simple Tweet for example (now with a 280 character limit rather than the previous 140 character limit).
The audience is quite different as well. You can, if you attract your audience well enough have them go on long binges and have them stay glued to the content of your channel for hours! Only if your content is good enough.
Some audiences prefer content to be posted more regularly while others prefer having it only once a while at predetermined timings. Here are two distinct examples:
- Wehsing (aka Singsing) an ex-professional Dota2 player who posts around 5-6 videos varying from 6-20 minutes each daily. The audience of Wehsing are people who are into gaming and enjoy his comedic outlook and peculiar personality through highlights of his streams (which are usually 1-1.5 hours long per game). This is why he can post content that often without boring audiences.
- On the other hand, Last Week Tonight’s channel posts videos usually on a regular schedule once a week on Mondays – usually by early morning in Europe which is around midnight in the United States.
This is why it depends on how you get your audience, what monetization types you have and other factors! It is always advisable to upload regularly, this makes it easier for you not to lose your audience because of all the other channels they’re following. A video at least once a week should be enough to keep your audience engaged but more may be needed depending on the nature and depth of your videos.