Another thing to do is search for the words "qual" "qualify" "qualifying" or "qualification" when it is slow to find HITs that are qualifiers for future studies or batches. Getting some good qualifications has led to me making some serious money from certain requesters.
Also keep an eye on the daily Great HITs thread for people posting about qualifying hits or batches. You can even go through the qualifications by searching for all of them and taking as many tests as you can. Some power users swear by this method.
Getting up your numbers
Do not neglect to do easy, low paying HITs when it's slow to build up your numbers.This has two benefits. First, once you get to 1000, 2500, 5000, and 10000, more HITs open up for you. Secondly, if you build a good "cushion" of approved HITs, you can take risks with new requesters and afford to risk a reject or two.
Note on new requesters
When it comes to batch HITs or high paying surveys/tasks, I always follow up my submission with an email welcoming them to mTurk, asking if my work was acceptable, and stating that I'll leave them their first positive review on TO as soon as they approve the HITs. I've had some requesters respond immediately with ways I can improve my work for them and make it easier on myself, while at the same time approving my older work that wasn't exactly right just because I was willing to communicate and ask for feedback. I've also gotten some quals this way.
Requesters/HITs to watch for
NOTE: This list was last updated on 4/12/2013. Requesters may change over time, and this list will be updated periodically to reflect that.
Add some of these to page monitor/check4change and get working for them immediately. I've made this list over the past three months and it comes from the requester list in the HIT Database meaning these are either the requesters I've made the most money from, or have been able to do a lot of HITs for in a short period of time. The first list is a money makers list, the second list is for number building.
R H - can also find by searching CCMath, requires qual, not sure when they're going to give it out again
Christopher Malon - posts .30 batches of "write questions to a sentence." Seem hard at first, but are really easy once you get the hang of them. Take me a minute or less a piece now
CrowdFlower - more specifically, search "crowdflower speech" for their comparing two audio clips HITs. It's a batch posted almost daily that pays decent despite their other HITs.
Behavioral Lab - posts surveys that most always pay more than .10/minute
Mary Pyc - I've done 2 $10 HITs that took 20 minutes or less from her in the past month, not sure if she'll be posting more, but worth keeping an eye out for
Andrew Carman - posts food sorting batches that pay .15 for less than 30 seconds of work.
heather walters - Posts $9-$10 HITs that take about 30-45 minutes every now and then. If you haven't worked for her, keep an eye out for her qualifying HIT.
Gabe - Posts surveys, almost always more than .10 a minute
SMT Inc. New requester, did some "find the facebook, twitter, etc page for this person" HITs for them the other day. Did 34 in less than two hours at .50 a piece for a total of $17. I hope they post again in the future.
Tyler Quick Posts writing HITs that are easy to do
Crowdsource - Not only are their search HITs good when it's low, but their "Judge the Sentiment" HITs pay really well and are easy to do. Search terms for this should be "crowdsource sentiment"
Acme Data Collection - record words for them, pays really well
Project Endor - Another recording HIT, they also have smartphone specific HITs that pay really well
Yale Cognition & Development Lab - Another requester that posts consistently good surveys
Agent Agent - Posts very quick icon testing surveys for .30 a piece
Pick Fu - Posts single questions surveys almost everyday for .04 a piece
Jaime Arguello Search engine HITs that are very easy and pay very well. I've been cut off from them for months though (was able to do about 50 for him)
DataJam LLC - Sorting through twitter photos, very easy
Venue Quality - Tell if two locations are the same, easy qual test
Homezoo - describe pictures of houses, they go quick
Redwood - Specifically their "review a short transcript >10sec" HITs. Search terms: Redwood review transcript"
GoGo - Similar to Venue Quality, but .02 a HIT and posts bigger batches (up to 200 at a time)
Readabl - Once you get to 2500 HITs approved, you can do these. I've done over 700 with only 3 rejects, although other people have been less lucky with them. You get the address off from mail and it takes seconds.
I hope this helps and you're able to increase your earnings with this information! If you have anymore questions, don't hesitate to ask (if it's about a script or add on, check the appropriate section of the forum first though!)
Take care and happy turking! =]