There are a lot of survey companies out there, many of them not really worth joining, but some are exceptional. Pinecone Research is one that is well worth joining.
You might not get many invitations but you will earn £3 for each initial survey - then you may aget a product to test. If you do then test it and keep it. Later you have a follow up survey which earns you another £3. This soon builds up and you get some quality good to test along the way.
They dont often take now people - but right now they are