Best way to earn STEEM by delegating SP

Some of us don't have time to write few articles per day or week. Up to now I wrote about one article per week and I find it unlikely to do more. I assume many are like me. We can thou still help the community to grow and earn some Steem at the same time. How to do that ? By delegating Steeem Power to other users and therefore enable them to grow their audience while you collect commission in Steem.

So far i have been using @minnowbooster. They have open market on their website https://www.minnowbooster.net/market where you can delegate your Steem Power (SP) to somebody for limited amount of time. You delegate SP to user, usually for 4 weeks. After that there is cool down period of one week and after that you get your SP back. Payout is quite nice, I get 1.254 per 1500 SP. The bad thing about it is that you have to repeat this procedure every 5 weeks, and there might not be any open orders for amount of SP you have.

I recently come across of @boomerang. It's also a bot where you bid against other users for upvote. There are several of those aveliable, but what it differentiate it from others is that users can delegate SP to the bot and get paid on every upvote. For 400 SP i get 0.04 on average per upvote, meaning 10 times a day.

What I like about it is that you have to delegate SP only once and that's it. Then you start receiving Steem based Dollars (SBD) every 2.4 hours. Not bad huh? Offcorse if users don't bid there wont be any payout.

I did some calculation to compare earning for both of these methods ATM.

By delegating 490 SP to market on @minnowbooster you get 12 Steem in 4 weeks. If we also calculate 1 week of cool down this means 0.3428571429 Steem per day for 35 days. This means that per each Steem delegated you get 0.0006997084548 Steem in return per day. In my case with 1900SP this would mean 1.329446064 Steem per day.

Now let's calculate for @boomerang. Delegation of 400 SP gives you payout of about 0.4 SBD per day. We have to then convert SBD to Steem. Current rate is 1.23. This means that per each SP delegated you get 0.0008130081 Steem back. So again with my 1900 SP I could get 1.544715447 Steem per day. Also according to @boomerang if they have more than 100,000 SP under control percentage of payout would be even greater. Im not sure if the return depends also on Steem price or not. If it does then great, if it doesn't then it's worth delegating untill Steem price reaches 1.43$ and after that use @minnowbooster instead.

So ATM i think it's best to invest in @boomerang. After my other delegations expire Im thinking delegating more SP to it. If you guys think there is better option and can buck it up with calculation I'm all ears.