I apologize in advance because I am a very long winded question answerer lol!!! So here it goes!
I will have to back up those who say that there really isn't an answer to your question that can be accurate enough for u to go by. No one knows how you use your phone, apps, your HTC sense account, ect. Only you do, so my advice to you would be to download the app that I have called "watchdog" . I recently switched from Verizon, where I had unlimited data to ATT where I currently have the 2GB per month. Since before I had unlimited data i never monitored my data usage because i didn't have the option of averages. I too wondered the same thing, "well how much data do certain apps, internet browsing, email, and you tube use?" That's when I stumbled across the watchdog app. It tells u how much data you are using and it counts it by MB and also converts it into a percentage for you. It also estimates how much data you will use by the end of your monthly cycle by taking an average of your daily data usage. I got my phone on April 18th and thats when I began to start my data usage. As of today. May 2nd, I have only used 776.2 MB or 37.9% of my 2GB, (if your wondering there are 1024 mb in 1 GB) which isn't very much at all considering I downloaded at least 50 apps since i got a new pgone and had to get all my favorite apps that I previously had, and I have all my weather animations on and my weather is set to update hourly, my children and I use YouTube for a few hours at a time, I check my email 30 times a day and also do Google searches about 30 times a day with each Google search being no less than 15 minutes! So to answer your question, there really is no answer to your question being that no body uses their phones the exact same way and therefore, cannot tell you how much data your phone will use! I can only give advice as to what I do on my phone and how I, personally, watch my data on my phone! Hope this helps
