The sentences are clear. I dont know if the word businesses can be used and i feel that replacing it with business would be appropriate.please think on that.I found the following sentence a bit odd "This is the reason why one of the critical success factors of e-commerce is its security." and i feel that it can be placed by " One of the reason for critical success factor of ecommerce is it's security". There isn't any problem with punctuation. The language was concise with out dragging too much about any topic.