In the first week I only offered the Flash version on my site (tinyworlds.org), later on also the HTML5 version. Generally there is to be said, that people seem to prefer HTML5 (didn't want to believe Flash is dead :P). However the higher percentage on itch.io can also be partly attributed to traffic from Twitter.
Also, as many of you may not know yet, you can also publish flash games on deviantART! I released some games before on there and in terms of views & comments it has been really pleasant! Your game needs to fit in the deviantART community tho, for it to work :) But back to itch.io!

As you can see, I got a lot of traffic from Twitter, mostly due this Tweet: I was able to pull additional people in trough the #screenshotsaturday hashtag, who were actually not looking for LDjam games. Also notable is the fact that the Tweet carries itself mostly trough the visuals, the text only directs the viewer to the game.
Here are some statistics on how the tweet performed: There are a lot more impressions than engagements, but the rate is still really ok for me.
And here are some statistics about when I got the views (itch.io): The huge spike comes from the day I published the tweet.
If you're game is visually simple and interesting enough and/or humorous, Twitter might be a great place to get some additional views. In my experience other developers are generally really supportive & will retweet your game upon release, if they like it enough.

That's it for now! I hope you found this useful :)
If you want to do me a favor, please play my LDjam game and leave me a comment please:

Click here to play