Being an affiliate, is it necessary to buy traffic?

Buying Traffic is a great way to increase your commission..but always prefer honest sellers, that puts your ad in front of real human visitors...

In a word No...

It can be useful to track your conversions when starting your own product but as hashif16 says above it is much better to get organic traffic that has a relationship with you as they will be more likley to buy from you again in the future.

Its a good way but you should have good real & targeted traffic so have conversions.

I have several free online games and I added some MMORPG affiliate (multiplayer online games), and I need to bring traffic to my website.
After the Panda update it very hard to progress in organic SEO, so I need to come up with other creative ideas.
I do use AdWords campaign and other forms of paid traffic, but it's not enough.

Any suggestions?

I assume "buying traffic" is any form of paid visitor generation, usually in affiliate marketing this is PPC, CPV or banner media buys.
This alternative for those who have operating cash but not the time and patience to gradually build up organic sites using seo. These days it takes a considerable amount of trial and error testing to identify profitable offers, expect to at least spend twice the payout value for each offer while testing candidates, and having to test 5 or 10 offers before identifying a winner.
Those with a knack for finding winning offers who spend thousands a week on media buys can make a real killing.

I found the Conversion Classroom WSO's 10 hours of videos nicely covered the different paid forms of traffic, this course is about 9 months old. (I have no connection)

I have worked real hard on my organic SEO, I got 8 HARD keywords to G first page, but the Panda update hit me hard, and I can't get the keywords back, no matter what I do.
This is why I'm looking for other directions.
So what you are saying is that I need to spend a lot of money before I can earn some? Did I understand you correctly?

Yes, BUT only if what you're paying is less than your commission... (duh!)

But really, that's the key factor. With paid traffic you can scale up, up, and up...

With free traffic, you're somewhat limited.

Here's what I recommend and what I do: Focus on as much FREE traffic as you can, because there's a ton of different ways to drive free traffic. But you can't focus on that solely by yourself. Get a virtual assistant once you have free traffic coming in and you're making good commission. That virtual assistant will be tons of help.

AND

Get into paid traffic once you're getting good conversions with free traffic (if you have money to invest and want to jump into paid traffic, do so, but do it slowly and with small amounts of $$$). Test and tweak, then scale up.

Paid traffic is great, but you will most likely lose money before you make money. I lost about $200 before I made my first $100 with paid traffic. So you can imagine when $200 was already out of my pocket, I was getting REAL nervous. But I kept it going, made some tweaks along the way, tested, tested, and tested, and then came the 1st profit. Be ready for that.