I've been watching your stream a lot lately, and I enjoy it tremendously. Thanks for the huge effort you put into it on a daily basis, I really appreciate it.
I think you are doing a great job. However, there is room for improvement.
With all the negativity flying around in here, I figured I'd try a different approach.
Here's some constructive criticism and advice. You can do with it what you want, as it's only meant to be a helping hand.
1. Be objective at all times. I know it can be difficult, we all have our favorite players, but it really is one of the most essential things when casting games for a mixed crowd.
2. Ignore the obvious trolls or people who don't respect your wishes. (Messaging you in-game etc.) You will come off as a much more professional caster if you ignore stuff like this. If someone messages you in game, simply block the person and continue casting the game. It makes you look bad if you start ranting about peoples lack of respect in the midst of a game. It's much better to politely remind people of this, in between games, so the game itself becomes uninterrupted.
3. No profanity. We all enjoy to use a bit of profanity when chilling with friends, however using profanity during a casting session is never a good idea. It's not too big of a deal if it slips once in a while in a heated in game moment, but you should always try to avoid using profanity. This is especially true, if you one day find yourself sponsored by a big cooperation.
4. Never insult the opposition. This is one of the biggest mistakes you can make. Never talk bad about your competition, instead talk about all the good things about your stream. All the great games you've casted and all the great games that will be casted in the future. People get put off by someone telling them, how much better they are compared to others, or how bad the others are, even if it's done with finesse.
5. Crying will always make you look bad. If you absolutely need to complain about something, do it in a professional manner, and get it over with fast. Viewers hate when a caster gets butt-hurt, so avoid that at all costs.
6. Respect the players at all times. The players are your key to success, not the viewers. If you get really good relations with the players, especially the top ranked ones, then I assure you the viewers will come. Never talk degrading about players (Unless they truly deserve it. I'll let you be the judge on that one) and when questioning their in-game decisions, do it in a manner that doesn't make them look like idiots. Remember you are streaming for a huge audience, how you treat them will reflect back on you.
7. Never talk to either player, discussing in game events, if the series is still undecided, it really is inappropriate. There's always a chance you might give away information unintentionally.
8. Mentioning your sponsor in between games is of course needed. Make sure to do it in a fast and precise manner. Tell the viewers the essentials, but try to avoid drawing it out. If people are interested in your sponsor or simply wants to support you by checking out the website, then they will easily figure how to sign up, and how to use the website etc. No need to go into details about that.
9. Analyze, analyze, analyze. Viewers love when someone else, in this case the caster, does all the thinking for them. Try to analyze every decision a player makes, and then draw a conclusion. This is what makes casters like Tasteless and day9 so good. This is what divides the good casters from the great casters, and the great casters from the true amazing casters. A decent caster will tell the viewers what he sees, but the great caster will tell the viewers what he sees and then draw conclusions based on this.
10. Knowing as much as possible about the game, is necessary to becoming a great caster. Being a diamond player, you probably know a lot more than I do. However, if you feel your knowledge lacks in some parts of the game, this could be a specific race or unit, I suggest you somehow get to know that race or unit better. This is really important and is a necessity for drawing competent conclusions.
11. Diversity is a good thing, it keeps the game fresh and the viewers entertained. Therefore try mixing up the games as much as possible. This means getting a good mix of races represented. Also try to mix up the players. It's nice to ask the viewers what game they want to see, but tbh the outcome is pretty obvious. Instead you should also go for the less known players once in a while. What you defiantly want to avoid at all costs, is the perception of player bias from your side, within the player base. That will only reflect back on you in a negative way.
12. Even though you think you are super awesome and know it all ( don't we all ), it's always better to take the humble route. This is one of the reasons Trumps stream is so popular, besides the awesome content of course. You want to avoid coming off as arrogant, at all costs. Being humble at times, should counter arrogance.
13. Treat all the players with respect, regardless of their skill, unless they've done something to deserve otherwise. They are and will always be your number one asset.
14. Switch to USTREAM ^^
15. Don't read aloud what you write to players etc. It does way more hurt than good. As interesting as it may be, some people will just abuse it or misunderstand you, causing drama. Instead, in between games, if you need to do some maintainance/contact players etc. play some music for the viewers and get the business done.
That's pretty much it. I wish you the best of luck in your future casting endeavors