Being here only three weeks, I'm probably not the best person to answer this question; however, I do think I know the answer.
Some of the hubpages hits are from checking your own pages. I discovered this by the fact that I was working on a page one day and checking it a lot (I wanted to get it just right) and that page had a lot of hubpage hits that day.
The other hubpage hits are (you guessed it) from your fellow hubbers. Quite often, heavy activity in questions and answers and forums will bring this traffic as your fellow hubbers click on your icon to discover more about you and find themselves reading your writings. This is why I say participation in the forums and the questions and answers is a good thing as it gets the ball rolling on page hits.,
Of course, the holy grail is outside hits, as these have the highest possibility of generating revenue. Quite often, the hubbers hitting your pages will up their rank, making them more visible on Google and easier for outsiders to find - so, while the hubbers don't often directly generate revenue, they do indirectly get the ball rolling for this to occur.
As far as most of the traffic going to your hub about tattoos, I would consider that your money making hub and would see what you could do to put appropriate advertising on your page. Search Amazon for things a tattooer might buy and list those items and make sure your tags are directly related to your hub (and not just set to pull in traffic) as these tags will generate the adsense ads we all hope people will click on.
Above all, if you are starting to get outside hits then the snowball has begun to slowly roll down the hill. It's a good thing, so long as the ball continues to roll down the hill and gathers speed. This, in a sense, signifies you have hit on a topic that is evergreen (has the potential to draw attention on a daily basis).
So, what do you do now? You can watch your hubs grow or plant new ones, and I think doing the latter will further your career along much better. :)