Populus Live is another great survey site. The advantages of this site are that they are amongst the highest paying out there. The surveys come relatively frequently, I get at least 3 per week I would say and often more. Their rule is that they pay you £1 for every 5 minutes of your time. Most of the surveys are between 5-10 minutes long, so you can easily fit them in to your day. Occasionally you get longer ones which are obviously nice, as they pay more!
The disadvantages of this site are that you are required to earn £50 before you can be paid. You must be paid by cheque and you have to wait for this to be sent to you, by post which normally takes at least a month after you have reached the payment threshold. They do screen you out relatively frequently, but usually early on in the survey. They also have a hugely irritating template layout for their surveys which makes them very slow to load. In addition, they have even more vexing sets of questions to test that you are paying attention which basically feel like they are ‘trying’ to catch you out. However I put up with this due to the high payment for each survey.
Overall, I’d urge you to give this site a go since they pay well for surveys completed. If you’d care to share your experiences with the site, then please get in touch!