Ive had a search of this forum and have found a lot of threads from people promoting their own paid link building services. However I was wondering if I could hear from users of paid link building or other SERP services which services actually work and are the most cost effective? I'm a bit of a beginner and have my on page stuff pretty well optimised (H1, description, title tags, keyword density etc) for some reasonably easy niches where my site ranks between page 3 and 5 in google naturally with no link building. Ive been looking at places like seolace where i can get 100 PR4+ links for $25. does this sound reasonable? Any information would be much appreciated!