A/b testing in terms of creating and closing leads is important. With what snowmaker mentioned about the content marketing, I believe this would be a great time do the A/B testing.

If you already are familiar with and know how to A/B test, you can ignore the following paragraph.

Firstly, within you blog content area, there should be various calls to action. This is one great use of a sidebar to advertise your service. On desktop, after a user scrolls past a certain point(which means they're most likely reading the post) you can have one of those boxes that appear in the bottom right of the screen with an advertisement. Then within the content you should reference your service several times, but don't go overboard with it because that can get annoying. For instance, lets say you mention a drawback of a current interviewing process, you can then follow that sentence with a sentence in parenthesis plugging your service, or you can have it as a caption styled paragraph(slightly smaller text, italicized) under the paragraph which you mention the current pain point. Now here is where A/B testing comes in. After you release an article, watch the (hopeful) influx of traffic. Make sure you're collecting data on the number of page views for the post, views to your sales/service page, link clicks, 'close' clicks, members joined. After you see the traffic start to die down, post another article, repeat another 2-3 times without changing any of the marketing content. After the traffic dies down on the last article you posted, change some of the wording around on the calls to action and marketing and play with the phrases. Make sure you keep track of the changes you're making. Now go through this process again of letting the traffic die down and post another article. Continue these cycles of changing content a few times. When you've gone through about 4 or so cycles, it's time to look at the data. Look at how much traffic you received through each period where the call to action content remained the same and see how the users took to the marketing by looking at the leads to the sales/service page and number of members that signed up. See which period had the greater percentage of conversions and you can either stick with that or repeat the cycle again with the periods with greater conversions to see if there's a clear winner and to confirm the results. There's also the possibility that you may not see any difference in conversions. In this case you can either repeat the cycles again, or just go with your heart for the time being. Every 6 months or so it's a good idea to go through this process again as your audience/market for the content may have evolved slightly and you want to keep your calls to action up to date with them.