The lay odds have shortened to 4.80, which means the back odds will have shortened too. If you were to place a back bet to effectively cash your exchange bet out, you would have made a loss so there’s little point in doing so.
It’s just luck of the draw. Sometimes the lay odds will shorten after you place your lay bet and other times they will get longer. It all evens itself out over time.
There’s nothing wrong with going for long odds like you say and banking a bit more profit. This is a free bet streak offer though so some people may wish to go for lower odds and maximise their chances of hitting another free bet.
The offers posted on this blog are representative of what can be achieved with a full set of unrestricted accounts. It’s something I’ve acknowledged a number of times in the past and there’s a note to that effect on the homepage.
Whilst I do still place some matched bets from time to time, running the blog is very much a full-time job and my main focus is to provide a service that helps people make some extra cash like I have been able to.