I believe the net proceeds from the play-off series excluding the Grand Final are split between the eight qualifying teams. The net proceeds of the Grand Final (after costs and the RFL's cut) are split between the finalists.

There is definitely a financial implication of not making the play-offs although as attendances in these games have tended to be low in recent seasons it's not necessarily make or break. Having said that year on year failure to make the top eight will have an effect, as Bradford have discovered.

Hi Steve. We had a specific problem with finance threads for a while, the details of which I can pm you if you're interested.
It's actually nice to have, what is after all an important issue, discussed sensibly. For Rovers, I'm not sure that prize money will have been that valuable to us. We've made the play-offs these last 3 years, but haven't gone far in any of them. In contrast Bradford went to 5 Grand Finals in a row, so that will have been a much more pronounced loss of revenue, I imagine.
The more important impact would perhaps be in gates falling, if performances and results don't improve, and being less attractive to potential signings. As you say, it is still fairly early in the season and for a transitional season 3-1-6 is disappointing rather than horrorific. We're playing poorly at the moment and that was cruelly exposed yesterday.
That a shortish-term downturn in form can potentially threaten a club's long-term viability, suggests we are, as Hudgell says, building on foundations of sand. Apart from maybe Leeds and Wigan, all the English clubs is SL have been giving of distress signals of one type or another. The recession is biting hard, on the RL demographic particularly so. There seems to be an appetite for change amongst at least some of the club chairmen. Interesting times ahead.