Is there a magic number when it comes to link-building? Can I hurt my site by being too overzealous?
Since you posted this in the “black hat” category I’m assuming that you’re looking for an appropriate answer. The easy answer is, “all of them”. The more detailed answer is whatever you need to rank. For me personally I care more about the total number of linking domains rather than the total number of links. 1 link from 25 domains is more valuable than 25 links from 1 domain. For black hat links, consider the likelihood of your links looking like spam, if they look like spam, you are probably going to be penalized. If you’re focused on a churn and burn strategy that is probably OK.
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