Here is my recent experience with Viva and their Free Trial. A few years ago I advertised on Vivastreet for a few months, like someone else said you do get a HUGE amount of TWs/idiots etc but I did get a few genuine clients.
I kept receiving texts advertising the free 'deal' and kept ignoring them, thinking they were just spam/fake or whatever. However recently having found myself back in Scotland I decided to take them up on the deal.
Its for a month, you get the full shebang - the advert is highlighted, featured and automatically reposted. You also get unlimited changes of location. So its more prominent than the average ad.
I found that particularly during the first two weeks I got massive amounts of TWs and very few clients, it picked up a little the last fortnight. Don't expect huge numbers of clients unless possibly your prices are very low. However for a free deal I wasn't complaining.
But if you were to pay for all the features rather than take out a basic ad, I believes it costs up to ?270 so probably not worth it. You have to have the patience of a saint with all the TWs too.
Strangely once the trial had ended I got an emails inviting me to another 'free trial'........however right at the end it says its for new customers only so don't know why I recieved it.
There were a few problems with my phone number bot showing - they have a system whereby your number is protected which you can opt in/out of. At least 2 or 3 times I noticed my number wasnt showing. Whilst they were very helpful when I emailed them about this (especially in comparison with a couple of years ago if you needed help from them) I wouldn't find this acceptable if I was paying for the ad.