It means you will use it in the future over a period of time. I am going to be using this tent for my next camping trip. I want to choose a new car carefully because I will be using it for at least 5 years. compare with : I will use this photograph in my presentation tomorrow. (use once) I will use a better book if I can find one. ( a general statement)

Instead of using two gerunds back to back split by an auxiliary verb it is likely better to stick with the future tense directly which makes the language fairly simple and understandable! I will be using this product - is fairly considerable!

Because the phrase was written in the gerund.

is it really correct sentence ?