Google has lifted the limit restrictions.
It’s important to note that while picking the number of ads, you should think about the short posts on your blog.
AdSense has explicitly mentioned:
“Currently, on each page AdSense publishers may place:
– Up to three AdSense for content units
– Up to three link units
– Up to two search boxes
Publishers may not place more than one “large” ad unit per page. We define a “large” ad unit as any unit similar in size to our 300×600 format. For example, this would include our 300×1050 and 970×250 formats, our 750×200 and 580×400 regional formats, and any other custom sized ad with comparable dimensions.”
- Adsense Content Units
Adsense Content Units include text, image or rich media ads. Content units are available in these sizes: 300×250 (Medium Rectangle), 336×280 (Large Rectangle), 728×90 (Leaderboard), 160×600 (Wide Skycraper), 320×50 (Mobile Banner), 234×60 (Half Banner), 320×100 (Large Mobile Banner), 468×60 (Banner), 970×90 (Large Leaderboard), 970×250 (Billboard), 120×600 (Skycraper), 120×240 (Vertical Banner), 300×600 (Large Skycraper).
You can place up to three Adsense for content units on one webpage. This includes a maximum of one 300×600 ad unit (or similar sized ad) per page.
- Adsense Link Units
Adsense Link Units are closely targeted to the interests of your readers. Link unit is one of the best performing ad units. It works great under navigation menu. Link units are available in these sizes: 728×15 (Horizontal Large), 468×15 (Horizontal Medium), 200×90 (Vertical X-Large), 180×90 (Vertical Large), 160×90 (Vertical Medium), 120×90 (Vertical Small).
You can place up to 2 link units per page.
Now, you can see in Google’s current ad placement policies that the ‘ad limit per page’ section has been removed. It has been replaced with a section titled ‘valuable inventory’, which cautions site owners not to let the amount of ads on a page exceed the amount of actual content. Doing so may result in Google limiting or disabling ads served on the page until appropriate changes are made.