Developers have highly sensitive and well-tuned B$ detectors. The marketing "techniques", e.g. SEM, SEO, CRO, Social - which you mention - are seen for what they are - manipulations of perceptions for unproven value propositions.
Developers are more interested in how your product solves their real problems.
For example, instead of your question, you could have posted a link to a blog entry where you state a problem and show how your product addresses it.
Anyway, as a gross generalisation, it is hard to generate much revenue quickly by selling tools to developers. They are more inclined to try before they buy. The value proposition needs to convince us that the return on investment is significant and worthwhile. If there is a comparable open-source solution then that is likely to be adopted.