And Mert was not in any way chastising you. It is always appropriate to ask. Certainly as you begin shopping, keeping notes of who shops what in your area, when they post etc. will help you get to the boards with appropriate timing to collect shops. Some companies are more predictable than others for certain types of shops, though more and more lately they seem to be dumping everything virtually simultaneously on their boards and within hours the jobs are gone. It is very frustrating--especially if it happens an hour or so after you last checked the board and you have been out on jobs only to discover on your return that fateful global email that the shops got posted in your absence.
With the abundance of shoppers out there, it is really mostly just the cheap shops that get bonused to get them done. Certainly if the pay and reimbursement are adequate to make the shop personally interesting to you, take it. Chances are there is someone even hungrier for work who will snag it otherwise. If a shop gets flaked, most frequently it is offered first to someone with a reputation for getting it done on the bonus round. Another reason to build your reputation with the company.
Now if we can get bunches of these folks back to work at good paying jobs, then perhaps there will be less competition for the scraps