Hi There
Welcome to Pherotalk 
Its smart to be skeptical the Internet is full of scams. I can tell you this is not one of them but you wont know for sure until you get to know the people here and use the products.
At least with your $25 GC and the small to-go bottles here you can give it a go without much cost to you.
Self effects are not felt by everyone and they tend to wain after repeated use because your body adjusts. Pheromones work more in the subconscious and you conscious of there presence when you use them.
I think you should start with AMMO and Ishine though. These are both great products. I would pop on down to the mens area and search for info on the scent choices for Ammo. I know the men have described them and you want to get something you like in scent. It comes by default in FF21 which many guys are reporting smells like detergent so you may want to pick another scent in the custom section if you choose a large bottle.
This link will give you some ideal on scent
If you have questions just ask there are a lot of great people here willing to help.
Tisha