Most conferences have been converted to strictly money-making entities.
Here is how it works:
- a RFP is published
- you submit
- you get a response: "Unfortunately, your proposal did not get accepted, however, we have a limited number of time slots for sponsors. If you become a silver sponsor..." In other words, you can submit any crap, as long as you provide "sponsorship".
This may or may not apply to DevOps Days, I don't know enough about it. Also, the above does not invalidate some good points made by the author regarding selecting the right angle of the presentation, etc.