In the blog post you quoted you can read the instructions to get Socialize:
Get 30% Off If You Have An Active JomSocial License
You don’t even have to pay the $99 that Socialize alone typically costs. If you have an active JomSocial license, Socialize is yours for just $69.99, a full 30% discount. Mark Zuckerberg paid millions, but you can have virtually all the fluid functionality of Facebook for just $69.99.
Enter the promo code “socialize” at checkout to receive your discount. Just remember for this discount to work, you’ll have to have an active JomSocial license.
Just add to cart Socialize and use socialize as coupon code. The bonuses are included in the package.
If you have more questions regarding this let me know.