Here are my thoughts on disadvantages of manual: 1. Manual wastes alot of time You can do exactly everything you can do manually with software, all you have to do is find a backlink, post it until a blog/platform approves it automatically, and then write a new submission text and keep posting it until another platform approves it automatically. It will look just as natural because you are taking the time to write a new link anchor and surrounding text. 2. Less Diversity You have to rely on manual to find a website, and once you've found one you will rely on that website. You end up having 45 domains with 4k backlinks while with software you can have 500 domains with 4k backlinks. With manual you are stuck using very few options. Work smart, not hard. 3. Backlinks research goes nowhere When you are working manually, you will usually use websites used by alot of seo's since your only search tool is google. There will be so many links there that yours will be devalued because you will find websites that have too much links devaluing yours. When you find a "seo used" website, it is monitored for backlinks so you can lost all those hours of work at once, while used software is like your own search engine meant for backlinks. Even though software initially uses google, it is a highly intelligent bot that is excellent at using its resources, it will find the pr you are looking for, the platform you are looking for, the ip range you are looking for (change search engine), and many more things. Instead of one search engine being used for an hour, you have 100 search engines being used in 2 minutes. 4. Keeping steady numbers daily/weekly/monthly (strategy wont work) manual may acually look unnatural Trying to get a steady amount of links from certain EXACT platforms daily/weekly/monthly? Theres no guarantee its going to get far. You may or may not be able to obatin them without help from your little friend software. It may actually ruin the balance and make you look unnatural, unless its a small project and only requires a certain amount of links. 5. 75% of the time you're discarding what you find Why so? Because you are wasting your time. Most of what you find will go in the garbage, you wont want to use that type of backlink, either not the right pr, either the wrong niche, either a bad neighborhood. Even if you want to go half manual/ half software you can. Just use the software to find a specific type of backlink and your all good. Disadvantages of Software 1. You NEED to know what you're doing Most SEOs that work alone or in a small company will have to use software for medium to big projects. If they dont know what their doing they will fail. 2. Makes you lazy You will find yourself thinking how easy it is to do with software while you're wrong, if you are using software properly, it shouldn't take 20 minutes to build 100 links, it should take 2-3 hours. That will make you fail. 3. Diversity could be limited If you choose the wrong software, or are lazy, it will result in the wrong diversity of backlinks, especially if you focus JUST on blogs, forums, and directories. SOLUTION Take ADVANTAGE of the good in both. Find links with software, post it manually.