I won't assure that commenting is gonna get you an alpha tester position. What you say in your comment is the key. Try to help with some feedback and if you have a question, just ask.
I became a tester and I had less than 20 comments (I was rejected in the alpha test competition cause that, duh!). I am the exception of the rule. What I did to deserve the position? Easy, I helped, not only with questions, I did it with solutions.
Take a look at my post and if you have an idea or question or whatever, shoot.
http://www.gprm.co.uk/forums/index.php?topic=5281.0Your game is needing YOU! (imagine a big finger pointing at you)
