Assuming you are both familiar with Skype and have logins, I can only think of two things that would stop this from happening. 1) One or both of you aren't mentally wired to ever be comfortable with cyber sex, no matter how hard you try. 2) There are some trust or attraction or communication issues on either side.
How familiar are you with her? Since you call her a friend, I'm thinking you haven't fooled around with her in person. That might make things more difficult.
My girlfriend and I were living apart for six months, but when we Skyped, I had complete faith that she wasn't going to be recording our sessions. So the trust part was fine. We were also very attracted to each other. The communication part was a no-brainer... we weren't going to be playing around with anyone else, so Skype was the only logical answer.
The only thing I didn't do was check that the internet was secure on her end... but maybe that's not even an issue. Skype is secure. My computer was fire-walled and my router was locked down. It helps in the being-comfortable department.
Paying someone to get off is fine for many people, but for me, I have never and will never pay anyone to get off. So I applaud you for trying this the free way. You just have to make sure you're both comfortable talking about it beforehand. And you both need to realize that the first time will probably be awkward... because unlike playing around in person, you both have to be cool with talking more; talking about how each other looks, how you're feeling, etc. I can't stress that enough. Finally, both of you have to be comfortable seeing each other get off. Sex is an intimate experience, and it's quite different when both of you aren't in the same room.
-gf