Hi Joris,
Yes to both of your questions, you got the two main points: it will boost your career, and makes a big difference on your CV for employers.

Of course an MBA makes sense for you only if you intend to go towards something like a management position..

To have a more detailed answer I would need to know which is your field of activity, where you want to work, generally speaking your career prospects.
greetings from Attiya

Hi Attiya, thank you for your answer. At this moment I hold a BBA, and I work as a business develop manager in a golf- and hotel resort in Belgium. But I am more ambitious then this. I would like to build an international career as business leader, in an international market.

I am really interested in the market of consumer goods but also in the world of consulting management, and therefore I would like to build a successful career in one of these markets.

I think that an MBA could be the right start?

Hi Joris,
I'm sorry for not coming back to you earlier, I overlooked your post.
For the two fields you are interested in, an MBA will certainly boost your career. But since it is a big investment, you should carefully chose the MBA.
If you have the profile to be accepeted in one of the internationally reputed MBAs, and if you have a way to finance it, that would of course be the best. Holding such an MBA it will certainly not be so difficult for you to find a good, well paid job. So there is a sort of guarantee that the investment will pay in the end.
If you don't get into one of those MBAs which have a name, you should prepare it thouroughly to make sure that those recruiters your aiming at, will acknowledge your MBA, and maybe as well chose a location where you can create contacts during your studies with the companies you are interested in.

Another advice I would give you is to evaluate the work experience you have now, if you have held enough positions of responsibilty, or management positions. Does an MBA make sense at this moment, does it look logical on your CV?
And besides your CV, do you have enough basis (knowledge and experience) that allows you to fully benefit of all the things you can learn doing an MBA?

Joris,

Some rankings have information about average salary and salary increase after the MBA. For example, I know that the Financial Times ranking has this info:

http://rankings.ft.com/rankings/mba/rankings.html

This should of course be taken with caution, because these data are as reported by the alumni, and because it is just the average. Presumably there's a lot of variation, which doesn't come out in the rankings, as far as I know. But it may give you a hint.

It may also be useful to make your own calculations and compute how much your salary would have to increase (pre versus post MBA) for you to be able to re-pay any possible loans and get a decent rate of return. Then you can see if it is reasonable for you to expect such a pay increase, considering your previous job and the labor market where you plan to look for a job.

Hi Joris, to give you a idea, in fact the average increase of salary is one factor defining how a program is ranked.
I would say that increase of salary is a major goal for many MBA students, together with concern to access management positions - interesting jobs with a high level of responsability.

But, as Jaitego states, these "promises" should be taken with caution, because in the end what matters is what you make out of it.