At Copyblogger, a long and useful list of 20 Mistakes that Will Undermine Your Call to Action and Cost You Sales. These are for commercial marketing, but almost all of them apply to fundraising:
Beginner mistakes:
No Call to Action
- Below the Fold
- Not Authoritative
- Not Specific
- Too Much Self Proclaimed Hype
- Multiple Calls to Action
- Puny Call to Action
Intermediate mistakes
- No Social Proof
- No Benefit to Signing Up
- Too Risky
- No Urgency
- Colors Blend In
- No Credibility
- Loaded with Jargon
Advanced mistakes
- Wrong Offer
- Undefined Sales Funnel
- No Empathy
- No Tangible Benefit
- No A/B Testing
- Never Studied Copywriting