ROIC<WACC, Growing BPS

Can anyone give any interesting insights into how firms that consistantly produce a ROIC below WACC can continue to grow their book value over time? One possibility I believe is acquisitions. By making frequent acquisitions, a company can grow its BPS by adding more and more goodwill. Anything else? What am I missing here. I find this hard to understand as a concept.

but under new IFAS, you can’t mark any goodwill anymore

What exactly does the new rule mean? That you cannot add goodwill to your balance sheet after an acquisition any more? Whystudy - do you have any insights on how firms with ROIC WACC. I am wondering if those statements are simply incorrect.