Cell adhesion in biology is attributed to a handful of specific ligand-receptor interactions, or common motifs such as RGD. Conversely, bio-technical situations such as the interactions between the body and implanted materials, assay devices contacting biological fluids, and even biomarine fouling will be largely influenced by nonspecific interactions. Indeed, some of the biological cell adhesive behavior may also be influenced by long range nonspecific interactions before ligand-receptor binding comes to bear. To that end, we ask the question: how much adsorbed protein is sufficient to produce adhesion at an interface which is otherwise substantially non-adhesive? Here we adsorbed different amounts of fibrinogen (from 0.05 to 5 mg/m2) on a model surface which is non-adhesive or minimally-adhesive: silica. When a series of these surfaces are exposed to flowing suspensions, we find that even though the net long range electrostatic field is negative, small amounts of fibrinogen, less than 0.5 mg/m2, are sufficient to give adhesion, either through hydrophobic interactions or through the interaction of positive regions of the protein with the approaching negative surface. We further observe that the adhesion “turns on” sharply at a distinct threshold, reminiscent of surface fluctuation studies with a purely electrostatic model. Hence this work not only answers the question “How much of a sticky protein can be tolerated before bioadhesion becomes a problem?”, it also demonstrates the role of fluctuations in protein-driven non-specific adhesion.