  Because of the short duty-cycles and observation-time constraints, studies of
bright TeV (E>100 GeV) blazars are mostly restricted to flaring episodes or
rather short (days to few weeks) multiwavelength campaigns. At the same time,
long-term studies of these objects are essential to gain a more complete
understanding of the blazar phenomenon and to constrain theoretical models
concerning jet physics. Only unbiased long-term studies are adequate for the
determination of flaring state probabilities and for estimating the statistical
significance of possible correlations between TeV flaring states and other
wavebands or observables, such as neutrino events. Regular observations also
provide triggers for multiwavelength ToO observations originating from the TeV
waveband. These are particularly needed to identify and study orphan TeV
flares, i.e. flares without counterparts in other wavebands. In 2007/8 the
MAGIC telescope has monitored three TeV blazars on a regular basis: Mrk 501,
Mrk 421, and 1ES 1959+650. We present preliminary results of these observations
including the measured light curves and a correlation study for VHE gamma-rays
and X-rays and VHE gamma-rays and optical R-band for Mrk 421.
