Advertising on TV, print, and radio typically requires a predetermined budget. What key differences enable some online advertising campaigns

Advertising on TV, print, and radio typically requires a predetermined budget. What key differences enable some online advertising campaigns to invest with more flexibility without a predetermined budget in mind? 

Or 

Print, TV and radio advertising typically requires a predetermined budget. What key differences enable some online advertising campaigns to invest with more flexibility without a predetermined budget in mind?

 

• AdWords budgets can only be set once annually and require a fixed commitment
• Online campaigns are highly measurable and can often automate a positive ROI. It can be strategic to capture all traffic without a predetermined budget as long as ROI is positive
• Online campaigns generate clicks, whereas other channels generate exposure
• Budgets cannot be applied to online campaigns due to constant changes in traffic

Correct answer is:

• Online campaigns are highly measurable and can often automate a positive ROI. It can be strategic to capture all traffic without a predetermined budget as long as ROI is positive