How to save 40% on your advertising costs according to analysis of 9,000 campaigns

A review of 9,000 Twitter direct response ads revealed the following:

1. The cost per acquisition (CPA) and click-through rate (CTR) of tweets including the terms hurry, fast, rapid, running out, and limited time are both 10% lower.
2. Tweets with a character count between 40 and 60 have the lowest CPA.
3. Tweets with questions have a 16% higher click-through rate.
4. Contest-related tweets have a 40% lower CPA.

It seems worthwhile to test it out for other ad channels.

Source: Twitter’s Blog