1. Intuitiveness of design 2. Simplicity 3. TOS/Privacy concerns; Can I delete my account and data with it? Who controls it? Who gets to look at it? 4. Use o

1. Intuitiveness of design 2. Simplicity 3. TOS/Privacy concerns; Can I delete my account and data with it? Who controls it? Who gets to look at it? 4. Use of open space in design of pages 5. Speed 6. Novelty factor 7. Connectivity with OpenID/Google account 8. Types of ads running on it 9. Customer service in case of problems; response time and vibe from site owners 10. Active development, new features, public API with decent documentation, and a good community around it 11. Does it fill a need that I have adequately/better than competitors?