Soap Operas were given that title because they were originally content marketing for Proctor and Gamble's soap. The enduring success of the format is due to the powerful connection created between the sponsor and the listener - it's clearly a really, really good marketing spend. 

There are a few things that Soaps have in common that are worth considering when thinking about Business-to-Business marketing:

Frequent

As noted in the quote from Wikipedia below, Soaps frequently broadcast on a daily basis. This enables the program to become part of a viewer's daily routine. As animals of habit, we love to be able to build our days around events that are reliable. Whilst for most B2B content, a daily publication might be a stretch, delivering a dependable resource that is of value to the reader on a regular basis helps people to build it into their schedule and to rely on it as a result. 

Short

Most Soaps are pretty short-form, meaning that the daily time-requirement is not overly onerous. This is an area where B2B comms have been repeat-offenders with expensive lengthy reports being given far more credit than they are due. 

Not about Soap

It's pretty obvious that Soap Operas are not about Soap, nor overtly about any products at all. It'd be annoying to have soap ads dropped into the content. Its the same for B2B content. Just don't do it. 

On-going 

The best and most successful Soap Operas fix on a winning format and do not change it meaningfully for years. "The BBC continues to broadcast the world's longest-running radio soap, The Archers, which first aired in May 1950, and has been running nationally since 1951". Target consistency in preference to an endless wheel of Marketing innovation.

A great example of this approach might be Tomasz Tunguz who has single-handedly delivered over a thousand comparatively short, brilliant data-driven posts about building a start-up on a weekly basis over many years. He has a huge profile in his industry.