1.Do I have to include my keywords in the title of my articles. 2.Can I still get traffic if I didn't include my keywords in my article's title.
1. Yes, and also mention them in the body few times 2. Yes, you will, but it's better to include the keyword in the title.
PUT THE KEYWORD IN THE FREAKING TITLE! You will lose soooo much traffic if you don't and there's really no reason why you wouldn't want to do that.
Bum Title = "My Keyword - Something catchy that will make them click" (keep it under 64 chartacter) SEO Title = "Keyword 1 | Keyword 2 - MySite.com" (Brad Callens suggestion anyway) Thats what I go with, If your not brining links into the equation, keyword in the title is the heaviest artillary you got mate.
Not only you should include it in your title, you should put it in the beginning of the title. It is possible to get traffic if it's not in the title, but your site would have to be some serious authority site with high PR or it would have to be some seriously non competitive keyword phrase. Otherwise - if your goal is to rank as high as possible for said keyword, DO include it in your title and preferably at the beginning of it. And it also should be in first paragraph of your article and several more times throughout the article, following proper keyword density guidelines.
Here's a trick I learned from Travis, the Bum Marketing guy. Make your title like this "keyword - blah blah blah keyword" for example "Internet Millionaire - Is it really possible to become an Internet Millionaire?" "Green Up Your Lawn - 7 Tips to Help you Green Up Your Lawn" Google will see the double keyword and sometimes give you a boost in the SERP beyond what you would have got with just the keyword in there once. Google will also highlight the additional relative words, which can draw attention to your title. Just make sure your title is readable, and catchy too.
Yes I remember this too, however you should be very careful with this, there's a chance that Google catches you as a keyword spammer. If you do this you better know what you're doing.
So far I've had good luck, it also works if your second instance of the keyword phrase is a variation, google seems to be getting better at recognizing related keywords and will highlight them also. Of course ezinarticles is only good for <50,000 result SERPs.