This is an awesome infographic on social media network ad sizes from our friends at Bannersnack.com

Expert use of ads on social media involves understanding these tips and tricks.

Facebook:

• Make sure your ad has a clear call to action
• 20% of your ad can be text. The rest should be a high-resolution image that conveys your brand personality.

Twitter:

• Make your ads compelling
• Test your cards frequently

LinkedIn:

• Give your audience a reason to pay attention to your ad
• Monitor your ad’s click through rate

Pinterest:

• For the best results on Pinterest make your ad
  • Helpful
  • Beautiful
  • And/Or Actionable

Google+:

• Keep your ad actionable
• Monitor comments and posts