We visited Old Navy and saw why it's Gap's biggest asset

In the entryway was a 75% off sign.

Denim was the first thing in the store. Everything was 30%.

Denim was also lining a wall to the right of the entrance. There was more to choose from then at Gap, and it was less expensive. Each pair cost $39 before the discount.

Old Navy had a huge variety of styles throughout the store, as it was clearing out summer inventory to make way for fall.

Most of the prices were pretty low — a striped t-shirt like this cost over $30 at Old Navy's sister store Gap, but only $15 at Old Navy, plus it was 50% off at Old Navy. The quality wasn't much different than Gap.

Old Navy's women's department was huge, and had a lot of variety in everything from t-shirts to business casual clothing.

There was also a lot of workout gear...

...and a ton of inexpensive accessories.

Old Navy had a lot of accessories, shoes, belts, and small products like hand lotion and face masks. Everything was under $20, with the exception of some shoes.

The lower level was divided between menswear, which had similar prices and deals to the women's department...

...and a huge clearance section that had a little bit of everything for under $10. Almost every style in the store was in the clearance section as well.

Old Navy carries everything — men's, women's, children's, accessories, and soon plus size — that Gap does, at the same quality, and for a lower price. After visiting the store it's clear why the brand is the main reason for Gap Inc.'s continued growth.