I'm trying to calculate the cost (real or imagined) of an MQL to incentive sales to follow up on those leads. Does anyone have a placeholder value or an actual value, and how did you calculate that?
This cost varies so much! From one market to another, from one organisation to another. Even the exact definition of what anb MQL is can vary and this variation impacts the cost.
Rule of thumb: sum up all the direct lead generation costs (meaning excluding all the team salaries, etc...) and divide it by the number of MQLs you generate in a year.
Do you have any cost attribution set up? If so, it's very easy to compute in RCA, overall, by channel, etc. If you don't, you could plug in a few basic costs like Greg mentioned above and then do the calculation. If you happen to have easy access to these costs and some ongoing overarching programs you can plug them into (i.e. attributing some portion of your Marketo license to your nurture streams), it might be worth the time it takes to do a more accurate calculation.