Medium Rectangle — 300 × 250

Where it goes

In the sidebar, or dropped into the body of an article after the second or third paragraph. Its near-square shape is the reason it is so forgiving: it does not need a full-width strip or a tall column to sit in, so it fits a template you did not design around advertising.

What it does to your layout

At 300 wide it fits inside almost every sidebar without forcing one wider, and inline it sits within the text column rather than breaking out of it. On a phone it scales down to the column width without leaving a gap, which is the main reason it outlives most other shapes.

What works inside it

Enough height for a headline and a line beneath it, so it carries an offer rather than just a name. Image ads should keep the important content away from the outer few pixels — some themes clip a hair off the edge.

Text ads are fitted automatically: the embed measures the box and grows the type until it no longer fits, then steps back one — so a short heading in a big slot is set large, and the same heading in a small one is set small, without ever overflowing or being stretched.

What to charge for it

The default reference point. If you run several sizes, this is the one to price first and judge the others against. You set the number, and can change it whenever you like. The calculator will turn a daily price into a monthly figure.