In what way, if any, does social media influence a small company's ability to advertise?

The ability of many smaller companies to advertise has not been affected by social media due to the greater benefit of larger companies.
Many smaller companies are now able to advertise on TV, radio, and websites, thanks to the rise of social media.

Many smaller companies are now able to advertise on TV, radio, and websites, thanks to the rise of social media.

Many smaller companies cannot afford to advertise on social media, but it does help spread word of mouth about their businesses.

Many smaller companies cannot afford to advertise on TV, the radio, or online, but they can afford to advertise on social media.