This video from HubSpot is humorous, but useful in that it displays the difference between inbound and outbound (or pull vs. push) marketing efforts.
By utilizing a company blog, social media, email marketing and other such efforts to distribute valuable content to a targeted audience (your ideal customers) you will be better positioned to be found online and create online conversions whereby you're capturing valuable prospect information in return for offering valuable content to that prospect. Thus, you're building a pipeline of prospects that you can continue to nurture with valuable content until they're ready to buy.
For the purposes of our video, let me ask, when was the last time you looked something up in the phone book vs. Googling it?
Essentially, that's how inbound marketing works--create content, boosting SEO, get found online, create conversions, nurture prospects until they buy, improve the process and start again.