Wow! First off, you're killing it! Very well done. 50k is an amazing number that you should be proud of.
My recommended next steps is to build out your platform. You've got a fan base and steady traffic of new fans. Try to think of products (digital) that your fans would love.
What problems do they have that you can solve within the realm of your expertise/niche?
I highly recommend you take some time and listen to the podcast Smart Passive Income with Pat Flynn. If you don't come away with some ideas, you're headphones are broke. :)
I also recommend you look into the eBook/Kindle publishing space. You can easily combine multiple blog posts into small books which provide value to your clients. Check out http://kindlepreneur.com/ for top notch coaching to blow up your niche.
Once you have digital products, you can look into setting up drip email campaigns and direct response marketing. That's what I do for my clients at massivemedia.biz
And, if you're still hungry for inspiration, check out Side Hustle Nation to listen to folks who've rocked their niches.
Keep up the good work. You've got something to build on for sure.