at least if the op would have added some info on this you'd need proxies accounts and then you're set. a little blackhat-ish
Interesting path to some pocket change ... one of many such little 'tricks' ... I always advise my clients to "BUILD A BUSINESS" and stay away from clever little tricks because they never last and they are never consistent. You are effectively selling to CPA merchants/advertisers ... BUT you can only do this once. You cannot profit from the same leads repeatedly the same way as you would from a customer base. Sure, some people respond to more than one or two CPA offers however they are the minority of your followers and this is not a repeat business model. The smart thing to do is (what someone suggested above): channel the traffic to your own Word Press site ... and build a following there and build the authority of your website and business. And with this strategy, of course you are neither limited to Tumblr nor are you at the mercy of what Tumblr decide to do to your blog/account. Never put all your (traffic) eggs in one basket.