Buying of delegation during the bear market can be devastating and might destroy your willpower, like it did to mine few months ago and since then I have totally stayed away from it.
Now that after HF20 things are taking a positive turn, and the price of Steem also slowly going up after hitting its lowest of the year. Buying of delegation is again profitable.
Those of you who don't know what delegation is, it's like renting Steem Power for a period of time and once the time is over the Steem Power is automatically returned unless you go for a renew.
For example, you can buy 1 Steem for $0.9 at today's market price, or how about you pay $0.9 and receive 20 Steem Power for 90 days? Sounds like a deal.
There are good sources to rent delegation such as 
Check them out, they all have different rates and durations.
Delegation will give a boost to your SP and your votes will generate bigger rewards. The only thing is in order to recover the cost, one has to self vote a lot, or do vote-for-vote with another person if they don't want to get the attention of flaggers who flag people for self-voting. In any case, with how things are going, it will be very easy to recover the cost and will also allow some additional profit. Recently I have got some delegations and I'm planning to rent some more this week.