There are several sites dedicated to specific platforms where you can outsource social media jobs and get fairly detailed reports back. These may be a good choice if you have clients who require more sophisticated services and who are willing to pay higher prices.

BuyPlusFollowers sells Google Plus Ones, Google Circle Followers, and Google Plus Shares. Pricing runs:

• $9.99 for 100 Google Plus Followers
• $51.80 for 1000 Plus Ones or Shares

BuyMoreLikes sells Facebook Likes, Comments, 5 Star Ratings, Share, and more. Pricing starts at:

• $5 for 50 Real Facebook Likes or Facebook Comments

CoinCrack sells Twitter Followers and Re-Tweets. Pricing starts at:

• $9 for 1000 Twitter Followers
• $9 for 100 Re-Tweets

Similar sites exist where you can buy Pinterest Likes and Pins, Digg or StumbleUpon Votes, Reddit up-votes, YouTube Likes or Subscribers, and Instagram, Delicious or Tumblr services, Etc.