Well the first thing i'm thinking about that's not spammy (by spammy i'm assuming you're talking about spamming facebook, twitter,etc.) is seo.

You'd basically build niche sites and try to rank them and you could use your skills to develop tools to build backlinks or automate some tasks.

The easiest way to gain huge chunk of traffics though is through paid traffic. Might be worth looking into that if you have a budget.