Hey guys, I have few questions about tier link building. 1. Is tier link building effective in 2015? 2. What are the criteria for tier 1 links? (PA, DA and PR if there is any other pls mention) 3. How many links should I use for tier 1? 4. What type of tier 1 links I can use for maximum SERP rank? 5. Can I use low quality GSA blasts as tier 3 links? 6. Can I use 301 redirect as tier 2 links 7. Do I have to use diversified anchor texts (keywords) in tier 2 and 3? I find many link building threads here but most of them don't cover these small questions. so I hope to get many useful answers. Sorry for bad English. Thank you!