You are correct, their wage is different, as their duties are different from the cabin crew. The CSAs are there for service only; they do not have any safety aspect to their official duties (although of course the girls would get the crew immediately if they see anything unusual) They are not required to complete SEP training nor participate in cabin service so the salary reflects this. I believe their flying pay is also less, but the allowances for layovers are the same for everyone.
On ULR trips two are carried; they generally share a hotel room on those trips (which I think must drive them crazy after 14hrs together)!
All in all the CSAs are a lovely bunch, never complaing (bar one exception I met once but she was just that- an exception) most of these girls are sending money home to their families too. Of course they have to clean toilets sometimes but this is something that all of the crew should be doing. Oftentimes we'll do the toilets ourselves but the girls will help us as they have the proper supplies for cleaning and also have more stock to replenish e.g. toilet paper, tissues etc.
They also have a different uniform so the passengers can tell them apart, still, the poor things always seem to get bombarded with requests for a drink on their way down the cabin.... which of course we will get for them as they will come tell us who wants what.
I'm told at the moment there aren't any who have become CC however I did hear this might be changing soon. A lot of them wanted to be CC but were offered the CSA job instead. I have a feeling they get recruited for their 'nice' personalities and I think some of them might be TOO nice for some of the passengers we get on board, if you know what I mean. They are also a varied bunch, some of them were doing the same thing before (hospitality/housekeeping), others have come from education or corporate jobs and took this opportunity for the travel and benefits they can get for themselves and their families.
Some people generalise them as maids and cleaners but they are a respected part of our team, not to mention very interesting to talk to
Hope this helps.