With the “happy, successful person” bit, commas are used to separate adjectives when multiple adjectives are used to describe a noun. To use “and” here would also be correct, but I don’t believe that that was her intention.

You are also correct about the use of “an”, except that it is not as cut and dry as only being used before vowels (and it is NEVER used before a Y). “An” is instead used before a vowel SOUND. If you say “HTML” aloud, you will hear that the way you pronounce “H” begins with a vowel sound. Think about it; does it sound natural to say “a HTML” when you read it aloud? “An” is correct here.

Man, I totally came off as a bitch just then. I’m sorry.

Thank you for the compliment on this review though.

I was pondering though about a few grammatical issued you picked up on. (You got my grammar mind thinking. :] )

“Avatars: “MSN, or forums or wherever” should be “MSN, forums, or wherever”
Isn’t it:
“MSN, forums or wherever”. You don’t use a comma with the last article or a list I believe.

“Being a happy, successful person”.
Same again here, shouldn’t it be “Being a happy and successful person”?

“a HTML” should be “an HTML”
I think it was originally correct because only vowels and ‘Y’ (sometimes) only require “an” instead of “a”.

I may be completely wrong Rachel, but I liked this review because it was really well written and structured as I previously mentioned.