Before the 300×250 Medium Rectangle took over the internet, the 180×150 Small Rectangle was a common sight. While it is now considered a legacy size, it remains a vital tool for websites with narrow columns or dense layouts.
It is perfectly sized to fit in the “left rail” of older website designs or to be used as a “sponsored tile” in a grid layout.
Why Use the 180×150?
1. Space Saver
If your sidebar is too narrow for a 300px wide ad, the 180×150 is the perfect alternative. It allows you to monetize space that would otherwise go to waste.
2. Text Ad Friendly
This size is historically associated with text-based ads or simple logo sponsorships. Because users are used to seeing it as a “link unit,” they often engage with it expecting useful information.
Conclusion
The 180×150 proves that you don’t need massive dimensions to be effective. It is a compact, polite ad unit that fits where others won’t.