Hi All I have done all the basic link building for one of my B2B clients and I even tried out the creative part i.e., viral marketing with infographics and it has not got any quality or decent natural links so far. The client does provide very limited support. The client is basically an HR services provider, tell me the different ways of getting a relevant and high quality links for the deeper pages on the site.
Find out the relevant blogs or sites and send him genuine guest post article request. You can put page hyperlink in author bio for relevant link.
Guest posting and content marketing are good options to build links for B2B sites. Social sharing works better for B2C.