The phrase "lower tier" refers to something or someone that is considered to be of lesser importance, quality, or status compared to others. Full definition
In short, there's still a lot of room for the car market — especially in lower tier cities — to grow. (stansberrychurchouse.com)
The difference between points and free night certificates is that the points normally offer you more flexibility in that you can stretch them further by using them on lower tier properties. (uponarriving.com)
[Hiring students from lower tier schools] is a nice sentiment, but I don't think it's about to happen. (legalblogwatch.typepad.com)